No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Clear cell acanthoma
Abstract
Clear cell acanthoma (CCA), is an asymptomatic benign lesion of unknown origin and aetiology, which typically presents as a red to brown, dome-shaped papule on the leg. We discuss the case of a patient with an irregular plaque of hypopigmented papules whose diagnosis of CCA was only made by biopsy, and review the characteristic presentation, uncommon variants, locations and associated conditions of this lesion. The diagnosis is based on histopathology and/or immunohistochemistry, but the variable clinical presentation may make diagnosis difficult. The differential diagnosis includes skin tumours and inflammatory and pigmentary dermatoses. The lesions do not regress spontaneously, and excisional removal is the preferred treatment.
... Dear Editor, Clear cell acanthoma (CCA) is a rare, benign, epithelial lesion with unknown pathogenesis. [1][2][3] Herein, we present a case of CCA developed during adalimumab therapy in a patient with psoriasis which raised the doubt of a paradoxical cutaneous reaction induced by adalimumab treatment. ...
... It most frequently affects middle-aged to elderly patients, manifesting as a very slow-growing solitary nodule or plaque up to 20 mm in size, with a thin, whitish, peripheral collarette scale, most commonly located in the lower extremities. 1 Uncommon forms of CCA, including giant-sized, pedunculated, pigmented, or eruptive lesions have also been described. [1][2][3] The etiopathogenesis of CCA has yet to be clarified. ...
... 1 Uncommon forms of CCA, including giant-sized, pedunculated, pigmented, or eruptive lesions have also been described. [1][2][3] The etiopathogenesis of CCA has yet to be clarified. 1,5 Most researchers consider it a benign epithelial tumor. ...
... In this paper, we describe a new variant of CCA and add another example of the rare polypoid variant to the literature. We also attempt to broaden the list of CCA variants summarized by Tempark and Shwayder [7] by adding ours and a few more examples of CCA, that have been reported before and subsequently, to their review. ...
... Several variations in the clinical and histological appearance of CCA have been reported. Most recently, Tempark and Shwayder [7] have attempted to collect and list these variants of CCA in an article. Interestingly, their accompanying case report is another unique presentation of CCA in a 4year-old African American boy which they did not include in their list. ...
... Several variations in the clinical and histological appearance of CCA have been reported. Most recently, Tempark and Shwayder [7] have attempted to collect and list these variants of CCA in an article. Interestingly, their accompanying case report is another unique presentation of CCA in a 4-year-old African American boy which they did not include in their list. ...
Degos and Civatte first described clear cell acanthoma (CCA) in 1962 and later in a review article found that, in most instances, the lesion was a solitary red-brown dome-shaped papule that involved the distal lower extremity. The first morphologic variant of CCA was reported as a “giant form of the acanthoma of Degos” which measured 45 × 40 mm, about twice the size of the largest CCA documented earlier. Since then, many variants of CCA have been described, including polypoid, pigmented and atypical. Herein, we describe a new variant of CCA and add another example of the polypoid variant to the literature. The new variant exhibits cellular features of trichilemmoma but architecturally differs from it. We also attempt to broaden the list of CCA variants summarized by Tempark and Shwayder by adding ours and a few more examples of CCA. The new variants of CCA include verrucous, linear, subungual and trichilemmal.
... Originally described by Degos et al. [1] in 1962, clear cell acanthoma (CCA), alternatively known as pale cell acanthoma, represents an uncommon benign epidermal tumor with strong predilection for the lower extremities, followed by the skin of the trunk and torso, and the scrotum [1][2][3]. CCA affects primarily middle-aged and elderly individuals between 50 and 70 years of age, with no frank gender preference [2,4,5]. Rare onset in younger patients has been reported [6]. ...
... Originally described by Degos et al. [1] in 1962, clear cell acanthoma (CCA), alternatively known as pale cell acanthoma, represents an uncommon benign epidermal tumor with strong predilection for the lower extremities, followed by the skin of the trunk and torso, and the scrotum [1][2][3]. CCA affects primarily middle-aged and elderly individuals between 50 and 70 years of age, with no frank gender preference [2,4,5]. Rare onset in younger patients has been reported [6]. ...
... Clinically, CCA manifests as a well-circumscribed, firm, elevated, dome-shaped papule or nodule with a brown or erythematous surface, measuring between 0.5 and 2.0 cm [2,6,7]. The red overlying surface of CCA can often appear crusted, exudative, and hemorrhagic upon minor trauma [2]. ...
Clear cell acanthoma (CCA), also known as pale cell acanthoma, represents a rare benign epidermal tumor with strong predilection for the lower extremities of middle-aged individuals and no frank gender preference. The etiology of CCA is poorly understood, although a localized psoriasiform reaction is favored. Herein, we report on the clinicopathologic and immunohistochemical features, and HPV status of an apparent example of oral CCA. A 58-year-old female presented with a well-circumscribed, asymptomatic, exophytic, sessile and erythematous nodule of the right hard palate, measuring 0.7 cm in greatest dimension. Microscopically, the lesion featured parakeratosis and acanthosis with neutrophilic microabscesses and broad elongated rete pegs. In areas, spinous epithelial cells exhibited pale or clear cytoplasm without nuclear pleomorphism, mitoses or cytologic atypia. The supporting connective tissue revealed mild chronic inflammation with few scattered neutrophils and numerous capillary vessels. PAS histochemical stain with and without diastase disclosed the presence of cytoplasmic glycogen in the pale cells. The majority of glycogen-rich epithelial cells stained strongly for EMA and were negative for D2-40. Ki-67 immunostaining was confined only to the basal cell layer of the epithelium. A diagnosis of CCA was rendered. The lesion was negative for human papillomavirus (HPV) infection, as assessed by HPV-DNA PCR using the MY09/11 primers for the L1 conserved region, thus HPV infection does not appear to contribute to the pathogenesis of oral CCA. In conclusion, we report an intraoral example of CCA in order to raise awareness about this entity.
... It is also known as "Degos acanthoma" or the "pale acanthoma" which is due to its histopathological features. It is an uncommon, benign lesion, most of the times, difficult to diagnose only based on the clinical aspect [1,2]. ...
... Other locations are: foot, thigh, abdomen, anterior thorax. Less common localizations include nipple, lower lip, toe, hands, genitals, suprapubic region, navel, scalp [2]. ...
... Other CCA-related conditions include: varicose veins, stasis dermatitis, seborrheic keratosis, bacterial dermatitis, viral infections, ichthyosis, xerosis, atopic dermatitis and insect bites. Evidence that clear cell acanthoma can be considered an inflammatory dermatosis includes clinical, histopathological, immunohistochemical and dermatoscopy appearance [2]. ...
ABSTACT: Clear cell acanthoma is an uncommon, benign lesion, usually present in middle-aged and elderly patients. It looks like an erythematous papule, solitary, with squama at the periphery, regularly located on the lower limbs. We present the case of an 80-year-old female, who was admitted in the Dermatology Clinic of Craiova for an infiltrative plaque, erythematous-squamous-crusty, well delimited, with sizes 1,2/1,5cm, polycyclic shape, located in the right groin. The onset of the condition was 7-8 years ago, with slow growth in size. The excision of the lesion was performed and the histopathological examination confirmed the diagnosis of clear cell acanthoma. Our case is atypical by location. Because clear cell acanthoma is difficult to be clinically diagnosed, with a wide range of lesions that make a differential diagnosis, we highlight the importance of histopathological examination for a positive diagnosis. The treatment depends on the type of lesion and on the patient's preference, usually consisting in surgical excision.
... The clear cell acanthoma (CCA), also known as the "Degos acanthoma" or as the "pale acanthoma" [1], is a rare benign lesion, with a variable clinical aspect and distinct histopathological characteristics. Firstly described in 1962 by Degos et al. [2] as "an epidermal tumor with a particular aspect", the rare clear cell acanthoma presented a special interest, because, clinically, it may be easily be confused with other skin lesions. ...
... Sometimes, it may have a polypoid or pedunculated aspect [6][7][8]. Most often, CCA is diagnosed in middle-aged or old-aged individuals, but it may also be found in children [1]. The lesions are usually localized at lower limbs level, but there were also reported localizations at the level of the inguinal area, scrotum, face, scalp, hand, trunk, nipple, buttock, forearm, head, etc. [5]. ...
... One of our case particularities was represented by the rapid development of skin nodular lesions, for approximately two months. Most studies showed that the clear cell acanthoma generally has a slow development of about two to 10 years, with reduced or even absent symptoms [1]. We consider that the rapid development of the acanthoma lesions were favored by the presence of various associated diseases, such as chronic venous insufficiency, which determined edema and stasis at lower limb level, and liver failure. ...
Clear cell acanthoma, firstly described by Degos as "an epidermal tumor with a particular aspect", although quite a rare lesion, raised an important interest because it may be easily confused with other dermatologic lesions, in the absence of a histopathological examination. Its clinical aspect is of a solitary nodule, with a red-brown varying color, with a size of 3 mm to 2 mm, sometimes covered with a thin scall. We present a case of a multiple rare cell acanthoma (seven nodular formations), having a rapid development (about two months) diagnosed in a 71-year-old patient within the lower 1÷3 of the right shin.
... Clear cell acanthoma (CCA) and squamous cell carcinoma (SCC) pose distinct challenges in dermatological oncology, highlighted by their rarity, varied aetiologies, and aggressive behaviour, particularly in the older male demographic [1]. SCC stands as the second most prevalent skin cancer, primarily driven by excessive ultraviolet (UV) light exposure, with risk factors including immunosuppression, arsenic exposure, and chronic irritation contributing to its development [2,3]. In contrast, CCA is a rare, benign tumour originating from keratinocytes, mainly occurring on the lower limbs but also seen in the inguinal region, trunk, forearms, face, and occasionally the nipple-areola complex [3]. ...
... SCC stands as the second most prevalent skin cancer, primarily driven by excessive ultraviolet (UV) light exposure, with risk factors including immunosuppression, arsenic exposure, and chronic irritation contributing to its development [2,3]. In contrast, CCA is a rare, benign tumour originating from keratinocytes, mainly occurring on the lower limbs but also seen in the inguinal region, trunk, forearms, face, and occasionally the nipple-areola complex [3]. The aetiology of CCA is not well understood, with some proposing it inflammatory dermatosis, evidenced by its psoriasis-like cytokeratin expression [4]. ...
Clear cell acanthoma (CCA) and squamous cell carcinoma (SCC) represent distinct entities within dermatological oncology, each posing unique diagnostic and therapeutic challenges. CCA is a rare, benign epidermal growth, often not associated with human papillomavirus (HPV) infection, whereas SCC, a more aggressive form of skin cancer, has been linked to both ultraviolet (UV) exposure and HPV. Understanding the co-occurrence of these conditions in a single patient can enhance diagnostic accuracy and therapeutic outcomes. We report a 64-year-old male who underwent an operation for a verruciform lesion in the right groin, which was diagnosed as HPV-positive CCA alongside keratinised SCC. A literature search across January 2024 revealed limited evidence directly linking HPV to CCA, suggesting a need for further investigation. The speculative association between HPV and CCA warrants deeper exploration, especially considering the potential for HPV to contribute to lesion development through indirect mechanisms. The coexistence of CCA and SCC in an elderly patient presents a unique clinical scenario. This emphasises the need for vigilant diagnosis and tailored treatment strategies, highlighting the gap in understanding the pathogenesis of CCA, particularly its potential association with HPV. Further research is crucial for elucidating the complex interactions governing these conditions and for developing targeted interventions.
... Clinically, CCA typically presents as a dome-shaped erythematous, asymptomatic papule or nodule, with a stuck-on appearance and a characteristic collarette of scale, classically described as "wafer-like" (2). The surface is either moist or crusted (4) and the lesion enlarges slowly over several years and ranges in size from 3 to 20 mm (4). Several clinical variants of CCA have been described, includ ing a giant, pedunculated or polypoid, eruptive, pigmented, atypical and cystic variant (4). ...
... The surface is either moist or crusted (4) and the lesion enlarges slowly over several years and ranges in size from 3 to 20 mm (4). Several clinical variants of CCA have been described, includ ing a giant, pedunculated or polypoid, eruptive, pigmented, atypical and cystic variant (4). ...
... El diagnóstico de acantoma de células claras puede establecerse sin la concurrencia de técnicas histoquímicas y/o inmunohistoquímicas si bien con técnicas de PAS puede ponerse de manifiesto la presencia de glucógeno en el citoplasma de las células claras, confirmándose el diagnóstico (Desmons et al., 1977;McKee et al., 2005;Kazakov et al., 2012;Tempark & Shwayder, 2012;Rotaru et al., 2014;Lever et al., 2015). La histoquímica también ha contribuido a aclarar la verdadera patogénesis lesional al demostrar la ausencia de fosforilasa en los queratinocitos "claros", poniendo de manifiesto la incapacidad de dichas células de degradar correctamente el glucógeno, fenómeno fisiológico tanto en los queratinocitos adyacentes como en aquellos que conforman el estrato basal que enmarca a las células claras. ...
... Como hemos comentado, no es necesario el concurso de técnicas inmunohistoquímicas con fines diagnósticos si bien en la literatura el acantoma de células claras ha sido intensamente estudiado desde esta perspectiva, caracterizando a la lesión de un modo más que minucioso (Desmons et al., 1977;Tempark & Shwayder, 2012;Rotaru et al., 2014). ...
Resumen
Introducción. El acantoma de células claras es una lesión tumoral benigna relativamente infrecuente que muestra unas características histológicas que permiten su diagnóstico. Método. Presentamos el caso de un acantoma de células claras abdominal, localización infrecuente, en un paciente de 72 años. Resultado. El diagnóstico fue establecido tras el pertinente estudio histológico pues la clínica inespecífica y la localización atípica impedían la realización de un correcto juicio clínico. Conclusiones. Pretendemos con la presentación del presente caso poner de manifiesto la histología tan peculiar de esta lesión al tiempo que, a través de una amplia revisión bibliográfica, mostramos distintas localizaciones y presentaciones atípicas de dicha entidad.
... Commonly, these lesions arise in middle-aged or elderly individuals and may also appear on the trunk, forearms, or face. CCA is typically managed with complete excision through shave biopsy, surgical excision, cryotherapy, or carbon dioxide laser (Tempark and Shwayder, 2012). Contrary to most cases of MCC, CCAs have an excellent prognosis. ...
... It may be covered with a thin crust and surrounded by a collarette of 'wafer-like' scales. Invasive removal have been preferred such as excision, curettage, electrofulguration, cryotherapy, and CO2 laser ablation 1 . ...
Clear cell acanthoma (CCA) is an uncommon, benign epithelial tumor presenting as a well-defined, slow-growing solitary nodule. The diagnosis of CCA is usually based on clinical and histopathological evaluation of the tumor. However, when such type of benign tumor occurs on an exposed area, a biopsy is not always the best diagnostic option since it may leave scar. The recent advent of dermoscopy has offered an accurate and non-invasive method to diagnose CCA without resorting to skin biopsy. A 40-year-old male presented with a shiny, erythematous-to-brown, flattened nodule on the left cheek. Dermoscopic examination revealed a 'string of pearls' vascular pattern, a characteristic dermoscopic feature of CCA. Under the clinical and dermoscopic impression of CCA, a 595 nm pulsed dye laser (PDL) therapy targeting the vascular tissue in the superficial dermis of the lesion was chosen for a minimally invasive treatment. After repeated sessions of PDL, an optimal cosmetic outcome was achieved and no recurrence was recorded during the follow-up period. Herein, we report a case of presumed CCA which was successfully diagnosed and treated by utilizing non-invasive modalities.
... However, cryosurgery remains a very useful alternative, espe- cially for multiple lesions [10]. ...
... However, cryosurgery remains a very useful alternative, espe- cially for multiple lesions [10]. ...
... 1,2 However, there is no scientific basis to establish an aetiological relationship between silicone implants and connective tissue diseases. 3 We report a case of systemic sclerosis (SSc) following silicone dermal injec- tions. ...
Acanthomas are benign proliferations of keratinocytes. Histological features include acanthosis, hyperkeratosis, dyskeratosis and acantholysis. Seborrhoeic keratosis is very common, appears in mid‐life and affects the majority of older adults. Clinical and dermoscopic features are characteristic. Certain somatic mutations are common, but the lesions are genetically stable and not premalignant. Surgery and cryotherapy are effective. Stucco keratosis is a variant in which white hyperkeratotic papules occur on the limbs in older adults. The dermatosis papulosa nigra variant occurs mostly in pigmented skin on the face. Warty dyskeratoma is rare and presents as a cup‐shaped nodule with a keratotic plug with dyskeratosis and acantholysis. Clear cell acanthoma is a red, dome‐shaped papule often on a lower limb with glycogen‐containing cells. Lichenoid keratosis is a solitary pink or brown plaque, mimicking other lesions. Pseudoepitheliomatous hyperplasia is a reactive epidermal proliferation occurring secondary to inflammatory or neoplastic conditions that mimics squamous cell carcinoma.
Benign keratinocytic acanthomas and proliferations are commonly presenting dermatoses with varied but distinct clinical and histological presentations. Whilst many such as seborrhoeic keratoses are easily diagnosed clinically, histology is mandatory in pseudoepitheliomatous hyperplasia as clinical distinction from squamous cell carcinoma can be very difficult.
Background and objective:
Clear cell acanthoma (CCA) is an uncommon lesion histologically characterized by the presence of epidermal acanthosis with keratinocytes containing clear cytoplasm. Although many single cases of CCA have been described, few case series have been published. The aim of this study was to describe the clinical characteristics of CCA in our practice setting.
Material and methods:
Retrospective study of patients diagnosed with CCA at Hospital Universitario de Bellvitge in Barcelona, Spain, between 1995 and 2021. We conducted a chart review to record age, sex, number and location of lesions, diameter, time since onset, clinical characteristics, suspected clinical diagnosis, and treatment.
Results:
Seventy patients (30 women and 40 men) with a mean (SD) age of 62 (13) years were diagnosed with CCA during the study period. Median (interquartile range) time since onset was 2 (4) years and median lesion diameter was 6 (5) mm. One woman had multiple lesions. Lesions were located on the lower extremities in 57 patients (81%), the posterior aspect of the trunk in 8 (11%), the anterior aspect of the trunk in 4 (5%), and the upper extremities in 1 (1%). CCA was clinically suspected in 40% of patients seen by dermatologists.
Conclusions:
CCA presents as an erythematous, dome-shaped lesion with pinpoint vessels and an epidermal collarette. The accuracy of clinical diagnosis has improved relative to earlier series, possibly due to a better clinical understanding of this lesion and a greater use of dermoscopy.
Background and objective:
Clear cell acanthoma (CCA) is an uncommon lesion histologically characterized by the presence of epidermal acanthosis with keratinocytes containing clear cytoplasm. Although many single cases of CCA have been described, few case series have been published. The aim of this study was to describe the clinical characteristics of CCA in our practice setting.
Material and methods:
Retrospective study of patients diagnosed with CCA at Hospital Universitario de Bellvitge in Barcelona, Spain, between 1995 and 2021. We conducted a chart review to record age, sex, number and location of lesions, diameter, time since onset, clinical characteristics, suspected clinical diagnosis, and treatment.
Results:
Seventy patients (30 women and 40 men) with a mean (SD) age of 62 (13) years were diagnosed with CCA during the study period. Median (interquartile range) time since onset was 2 (4) years and median lesion diameter was 6 (5) mm. One woman had multiple lesions. Lesions were located on the lower extremities in 57 patients (81%), the posterior aspect of the trunk in 8 (11%), the anterior aspect of the trunk in 4 (5%), and the upper extremities in 1 (1%). CCA was clinically suspected in 40% of patients seen by dermatologists.
Conclusions:
CCA presents as an erythematous, dome-shaped lesion with pinpoint vessels and an epidermal collarette. The accuracy of clinical diagnosis has improved relative to earlier series, possibly due to a better clinical understanding of this lesion and a greater use of dermoscopy.
Clear cell acanthoma (CCA) is a rare, benign epidermal lesion of clear glycogen-containing keratinocytes. The exact etiology is unknown. Although CCA usually appear as solitary lesions, cases of multiple CCAs have also been described. The rare eruptive CCA variant describes cases with more than 30 lesions.
Current therapeutic evidence for the management of multiple CCAs is limited. CO2 laser remains the most widely used laser in clinical practice. However, literature describing its effectiveness on CCA is sparse, and previous reports have described its use for a maximum of three lesions. To our knowledge, this is the first report of successful CO2 laser treatment of the multiple eruptive CCA variant with an excellent cosmetic outcome.
Our case adds to the evidence that CO2 laser is an effective treatment for this condition. Particularly in those patients with refractory or multiple eruptive CCAs, or for those who may not tolerate repeated courses of cryotherapy, or who are concerned about scarring and cosmetic outcome.
Zusammenfassung
Das Klarzellakanthom ist ein selten diagnostizierter Tumor, der aufgrund variabler klinischer Morphologie in der Regel erst anhand seiner histopathologischen Merkmale erkannt wird. Die Primäreffloreszenz ist eine wenige Millimeter durchmessende rote Papel, die als einzelne Läsion häufig an den unteren Extremitäten auftritt. In der Dermatoskopie gilt eine Perlenkettenstruktur der Gefäße (strings of pearls) als weitgehend spezifischer Befund der Klarzellakanthome. Im Gegensatz zu dem zunächst uncharakteristischen klinischen Befund ist das histopathologische Bild der Klarzellakanthome durch eine typische kompakte, scharf begrenzte Akanthose gekennzeichnet, bestehend aus hellen, PAS‐reaktiven Keratinozyten. Bei ungeklärter Ätiologie und Pathogenese ist auch die Nosologie der Klarzellakanthome umstritten. Diskutiert wird die Einordnung als kutane Neoplasie oder als reaktive inflammatorische Dermatose.
Clear cell acanthoma is a rarely diagnosed tumor with variable clinical morphology that is usually only recognized by its histopathological features. The primary lesion is a red papule a few millimeters in diameter that often occurs as a single lesion on the lower extremities. In dermoscopy, resemblance of the vessels to a string of pearls is a largely specific finding of clear cell acanthoma. In contrast to the initially uncharacteristic clinical findings, histopathology of clear cell acanthomas is characterized by a typical compact, well-demarcated acanthosis consisting of pale-staining, PAS-reactive keratinocytes. As etiology and pathogenesis are both unclear, nosology of clear cell acanthoma is also controversial, with an ongoing debate as to its classification as cutaneous neoplasia or reactive inflammatory dermatosis.
Clear cell acanthoma (CCA) is a benign epidermal lesion of epidermal keratinocytes which has a distinctive histopathology. Firstly described as a benign epidermal tumor, at the present, it is discussed if it is a true tumor or has an inflammatory reactive origin. Typical CCA is a red to brown, dome-shaped, solitary papule or nodule, often covered by a thin collarette of scale. The lesions usually present on the legs in middle-aged to elderly persons, without gender predilection. At the present, only nine cases of CCA on the areola or the nipple have been reported in the literature. On this location, women predilection is seen and typically presented as a chronic, erythematous, scaled, well-defined plaque, regarding chronic eczema. The preferred treatment is lesion removal, although anti-inflammatory treatment with potent corticosteroids should be previously done, based on reactive inflammatory dermatosis origin hypothesis.
Synonym: Lentigo actinica, Lentigo senilis, Altersfleck
Synonym: Lentigo actinica, Lentigo senilis, Altersfleck
Clear cell acanthoma (CCA) is a benign epidermal lesion occurring most frequently on the lower extremities of adults in the fifth to seventh decade of life. The etiology is unclear; it most likely is a benign neoplastic or a reactive inflammatory process. CCA is a slow growing, papular or nodular lesion, most often dome-shaped and red to brown in color. Diagnosis cannot be made clinically, given its similarity in appearance to other more common skin lesions. Histological examination demonstrates a well-demarcated collection of clear cells containing intracytoplasmic glycogen, which give this lesion its name. For single lesions, surgical excision is often the treatment of choice. However, cryosurgery is a very effective alternative, especially beneficial for patients with multiple lesions, lesions located over bony prominences not readily amenable to excision, or in situations where surgery is relatively contraindicated (neutropenia, anticoagulation) or not desired.
Clear cell proliferations of the skin consist of a diverse group of lesions characterized by the presence of cells with abundant clear cytoplasm. They may arise from primary, metastatic, or non-neoplastic origins, with their distinctive cytoplasmic clearing attributable to causes ranging from artifact to accumulation of materials such as glycogen, mucin, or lipids. Despite the heterogeneity of these lesions, their distinguishing characteristics may be subtle, especially at high power. As such, histologic diagnosis can be challenging, and proper consideration relies on an understanding of the scope of possible origins, etiologies, and key immunohistochemical staining patterns of the various entities. This review categorizes cutaneous clear cell neoplasms by histogenesis, and offers differential diagnostic strategies to aid in their clinicopathologic evaluation.
Although uncommonly diagnosed, clear cell acanthoma represents an original source of speculative interest for dermatologists. Due to its clinical variability, it is often only recognized accidentally after histology. Dermoscopy has improved the reliability of clinical diagnosis of typical clear cell acanthoma thanks to the vascular pinpoint pattern and desquamative, peripheral collarette. Generally, therapy of clear cell acanthoma is oriented towards ablative solutions, such as surgery or cryotherapy. We propose a conservative therapy, based on the application of topical calcipotriol, which has produced complete regression after 2 months and no relapse one year after the end of treatment. A dermatoscope monitored all changes of clear cell acanthoma, showing its utility not only in diagnosis but also in therapeutic follow-up. This new therapeutic approach should support an inflammatory etiology of clear cell acanthoma, although further observations are needed to confirm this.
Clear cell acanthoma is a rare solitary benign epidermal tumor of unknown etiology. The disease arises in the middle-age, with no sex predominance. It appears as a single reddish papule or papule-nodule and a peripheral scaling collarette is characteristic. Although solitary lesions are the rule, less than 30 cases of multiple Clear cell acanthoma have been described in the literature to date.
We report an unusual case of a healthy 74-year-old male with multiple clear cell acanthoma on the lower extremities treated successfully with cryotherapy.
Despite significant progress in treatment of clear cell acanthoma, cryotherapy, based on liquid nitrogen, remains an important alternative in treating multiple clear cell acanthomas.
Clear cell acanthoma (CCA) is a rare benign epidermal tumor. It usually presents as a flat nodule or dome-shaped plaque and is often localized on the legs of the elderly. We observed an unusual case of polypoid CCA on the nipple of a 14-year-old girl. At present, a few cases of CCA on the nipple area have been reported in the literature. However, CCA presented as a polypoid tumor on the nipple area has been reported very rarely. We herein report the very rare case of polypoid CCA on the nipple and suggest that CCA should be included in the clinical differential diagnosis of polypoid lesions on the nipple.
Background: The treatment of choice for clear cell acanthoma (CCA) is excision. Resolution after cryotherapy has also been reported but requires three to four courses of treatment. Objective: To demonstrate three CCA lesions in two patients successfully treated with a carbon dioxide (CO2) laser. Methods: Under local anesthesia, these lesions were vaporized by using a CO2 laser in the Silktouch mode with a spot size of 5 mm and a fluence of 20 J/cm2. Two to six passes, as needed, were delivered until the tumor was completely removed. Results: Pain was minimal or nonexistent during and after the operation. No postoperative edema was noted. The wounds healed satisfactorily without scarring. No sign of recurrence was found following operation. Conclusion: The CO2 laser has the advantages of requiring only one course, precise tumor removal, a relatively bloodless surgical field, a short operation time, and less or no postoperative pain and edema. Postoperative wound care is convenient and easy with hydrocolloid and alginate dressings. The patient's quality of life is less adversely affected. The CO2 laser may be appropriate for multiple CCAs, giant CCA, CCA overlying or near joints, CCA refractory to cryotherapy, patients on anticoagulants, and those who cannot tolerate pain from cryotherapy, especially children and the elderly.
We are reporting four additional patients with typical Degos' clear-cell acanthomas to emphasize that a clinical diagnosis is possible.
A single, 1- or 2-cm, slowly growing, domeshaped, sharply delineated, erythematous, usually smooth papule, stippled with tiny red puncta which blanche on pressure and marginated by a thin keratinous scale, suggests the diagnosis. Presurgical recognition may avert unnecessary radical treatment.
REPORT OF A CASE
A 38-year-old Filipino man presented for evaluation of a slowly growing papule on his left lower leg. The asymptomatic papule had been present for 1 year.Physical examination was remarkable for a 5×5-mm reddish-pink, firm papule over the medial aspect of the left lower leg (Figure 1). The papule had a flat, smooth surface centrally and a collarette of fine scale at the periphery. The skin adjacent to the papule had brown hyperpigmentation. The cutaneous examination was also remarkable for a Becker nevus over the right upper arm.A punch excision from the left lower leg is shown in Figures 2 through 4.What is your diagnosis?DIAGNOSIS:
Clear-cell acanthoma.HISTOPATHOLOGIC FINDINGS
Hematoxylin-eosin—stained sections revealed a sharply demarcated, acanthotic epidermis composed of large keratinocytes that stained lighter than the adjacent epidermis. Parakeratosis and an absent granular layer were
One patient with lamellar ichthyosis and one patient with ichthyosis vulgaris, both with multiple clear-cell acanthomas on the lower extremities, were studied. Histologic examination showed the typical findings of clear-cell acanthoma, plus intraepidermal nests composed of cell debris and inflammatory cells. Histochemical studies revealed increased dendritic cells with intense nucleotide triphosphatase and acid phosphatase activities. The dendritic cells also contained neutral lipids, well demonstrated by oil red O stain. Electron microscopic examination revealed, in addition to glycogen-containing epidermal cells, dendritic cells and processes in the intercellular spaces. Although indeterminate dendritic cells were found, many contained Langerhans granules and lysosomes. Leukocytes and products of cell degradation were seen in the intercellular spaces, often in relation to the leukocyte nests. Mast cells were observed in the epidermis.
† Clear cell acanthoma is usually a solitary benign epidermal tumor. Multiple lesions are rarely encountered, and only 11 such cases could be found in the literature. In all cases, the lesions were limited to the lower extremities. A few of the patients have had ichthyosis and/or varicose veins. We describe a 12th patient who, in addition to leg lesions, had lesions on the trunk and associated dry skin.
(Arch Dermatol 116:433-434, 1980)
We have previously reported the presence of carcinoembryonic antigen in eccrine and apocrine gland and duct and in all sweat gland adenomas. The absence of carcinoebryonic antigen in clear cell acanthoma suggests that this lesion is not derived from sweat gland epithelium.
Clear cell acanthoma (CCA) is a benign epidermal lesion with distinctive clinicopathological features. Multiple disseminated eruptive CCA is an infrequent clinical variant that has been rarely reported. It is characterized by the presence of more than 30 lesions from 1 to 10 mm in diameter that appear progressively over the years. We report the case of a 65-year-old woman with multiple disseminated eruptive CCA affecting her lower extremities. In contrast to previous reports, most of the lesions appeared in a short period of time (less than a month) and, what is more interesting is that some of them have regressed spontaneously leaving residual hyperpigmentation. At present, the histogenesis and etiology of CCA remain unknown. Accumulating data suggest a reactive origin associated with a variety of different inflammatory conditions. The case presented in this report further substantiates that CCA is indeed a reactive epidermal reaction pattern with an inflammatory etiology.
Clear cell acanthoma is a rare, benign epidermal tumor with a clinical hybrid appearance and a distinct histological one. It is frequently mistaken for other clinical lesions.
To evaluate the frequency that clear cell acanthoma was listed in the clinical differential diagnosis of histologically confirmed specimens.
A regional dermatopathology lab database was evaluated from January 1998 through March 2008 for histologically diagnosed cases of clear cell acanthoma. Clinical data that was submitted with these cases including differential diagnoses was analyzed.
During this time period of review, 411 histologically confirmed cases of clear cell acanthoma were identified. This entity was listed as a diagnostic possibility in 11 (2.7%) of the cases.
Clear cell acanthoma was rarely listed amongst the differential diagnosis of biopsy proven specimens. This may be due to a variable clinical appearance with overlapping features of several other lesions making it difficult to distinguish, or an entity that is rare and not frequently suspected. Additional studies with dermatoscopy may help to further delineate the reasons for the low diagnostic sensitivity.
Auteur(s) : Takamitsu Tanaka, Takako Arai, Takeko Ishikawa, Takamitsu Ohnishi, Shinichi Watanabe Department of Dermatology, Teikyo University School of Medicine, 11-1, Kaga, 2-chome, Itabashi-ku, Tokyo 173-8605, Japan Clear cell acanthoma is a distinct clinical and histological entity that was first described in 1962 by Degos et al. The clinical appearance is usually characterized by a nodule or plaque with thin scaly-crusts on the legs, although considerable variety exists. Silhouette [...]
Different patterns of epidermal change, including epidermolytic hyperkeratosis and acantholytic dyskeratosis, may represent the predominant histopathologic finding in several localized and generalized processes. Occasionally, minute foci of these reaction patterns are identified as an incidental finding in a biopsy taken because of the presence of some other lesion. Clear (pale) cell acanthosis may occur as the main histologic alteration in clear (pale) cell acanthoma or incidentally, such as may be seen within a seborrheic keratosis. Two cases of incidental minute foci of clear (pale) cell acanthosis are described and put into the broader context of other epidermal histologic reaction patterns.
Two patients with clear-cell acanthoma with multiple lesions are reported; histologic and histochemical findings are similar to previous descriptions. The ultrastructural study confirms the overload of glycogen in keratinocytes, associated with an increase of mitochondria and nuclear deformations. The abundance of Langerhans' cells is emphasized. Extrusion of glycogen by keratinocytes and its phagocytosis by Langerhans' cells is suggested.
Two cases of clear cell acanthoma (CCA) with marked signs of cellular atypia and mitotic figures are reported. Although the nature of CCA is not completely understood, it is considered to be a benign epithelial tumor. Our cases show that these lesions can develop malignant features.
We report on two cases of polypous clear cell acanthoma. This growth pattern is unusual for the tumor and has not been reported in the literature. Histologically, these two tumors fulfill the criteria of clear cell acanthoma.
The presence of melanocytes in 11 clear cell acanthoma cases was investigated by silver impregnation. Melanocytes were always present, their density showing great variability from case to case and within each individual neoplasm. The possible existence of a pigmented counterpart to clear cell acanthoma is discussed.
Two cases of clear cell acanthoma are reported. The expression of carcinoembryonic antigen (CEA), involucrin and keratin proteins in the tumors was investigated immunohistochemically. In 1981, Penneys et al. reported that this tumor was not of sweat gland origin because of the absence of CEA. This study confirmed this, further, the pattern of positive reaction of involucrin also indicated that this tumor is not of sweat duct origin.
Clear cell acanthomas (Degos' acanthomas) are usually solitary tumours and an excisional diagnostic biopsy therefore provides effective treatment. Such an approach is, however, impractical in the much rarer condition of multiple clear cell acanthomas where up to 30 lesions have been described on one patient. We describe a case of multiple clear cell acanthomas in which cryotherapy provided a quick and convenient method of treatment resulting in minimal scarring especially when compared to excision biopsy.
Two cases of clear cell acanthoma were examined. In both cases pale sheath cells of the eccrine sweat duct were shown to merge in the pale cell acanthoma. In some places the pale cells replaced the basal layer. These facts suggest an eccrine sweat duct origin for the clear cell acanthoma.
A 63-year-old man with clear-cell acanthoma of the vermilion mucosa of the lower lip is reported. The 143 previously documented cases, including two on the lip, have all been on the skin. The clinical and histopathologic features of clear-cell acanthoma tend to favor a benign epidermal neoplasm. Until its exact nature is known, it is suggested that clear-cell acanthoma be considered a benign localized squamous-cell lesion in which an intracellular enzyme defect has resulted in the prominent accumulation of glycogen and enlargement of the cell.
The clinical and histologic features of 37 new cases of clear cell acanthoma were analyzed. All lesions were solitary; most were asymptomatic, erythematous nodules less than 1 cm. in diameter. The median age of the patients was 64 years, the median duration of the lesions was 3 years, and the incidences in both sexes were equal. Thirty-five of the tumors occurred on the lower limbs. Many were clinically interpreted as basal cell carcinoma, histiocytoma, or granuloma pyogenicum. Histologic examination disclosed acanthotic rete ridges with large, pale, glycogen-rich malpighian cells covered by serous crust and parakeratotic scale. At each margin there was a sharp transition to dark cell acanthosis in two or three rete ridges which were covered by thick horn and a hyperplastic granular layer. Lateral to this was a second transition to normal epidermis. Rich vascularity and a perivascular lymphocytic infiltrate were present in the cutis.
An account of the histogenesis, histopathology, histochemistry and clinical features of the clear-cell acanthoma is based on the authors’ extensive personal experience and a complete review of the world literature.
Clear cell acanthoma is a benign neoplasm of keratinocytes usually occurring as a single lesion and not found with an underlying skin disorder. A patient is reported with generalized lamellar ichthyosis and scattered clear cell acanthomas. The meaning of this unique association remains obscure and is in all probability coincidental.Copyright © 1971 S. Karger AG, Basel
A clear cell acanthoma developed in an epidermal nevus of a 73-year-old man who had the Leser-Trélat sign in association with lung cancer. The occurrence of clear cell acanthoma is presumably related to the pathogenesis of the Leser-Trélat sign.
Clear cell acanthoma is usually a solitary benign epidermal tumor. Multiple lesions are rarely encountered, and only 11 such cases could be found in the literature. In all cases, the lesions were limited to the lower extremities. A few of the patients have had ichthyosis and/or varicose veins. We describe a 12th patient who, in addition to leg lesions, had lesions on the trunk and associated dry skin.
The expression of cytokeratins and involucrin varies greatly in different epithelia, and this raises the possibility that detailed analysis of these epidermal proteins might provide a means of identifying various skin tumours. The present study was conducted to determine the immunohistochemical distribution of cytokeratins and involucrin in calcifying epithelioma of Malherbe, in order to elucidate the nature and differentiation of this tumour. To correlate the immunohistochemical profile with the most frequent histological patterns, we categorized the basophilic, transitional, shadow, and squamoid cells, and the shreds of keratin. Comparative studies with normal skin showed that the shadow and transitional cells corresponded to hair cortex cells, the squamoid cells to the outer root sheath, the basophilic cells adjacent to the stroma to the outermost cell layer of the outer root sheath between the lower permanent portion and upper transient portion of the follicles, and the basophilic cells adjacent to the transitional cells to the hair matrix. The expression of cytokeratins in most shreds of keratin was similar to that in squamoid cells. Calcifying epithelioma was, therefore, shown to be composed of tumour cells differentiating into both the hair cortex and outer root sheath. These tumour cells were differentiated from basophilic cells, which showed the same staining patterns as the outermost cell layer of the outer root sheath between the lower permanent portion and upper transient portion of the hair follicles, supporting the hypothesis that the keratinocytes in the outermost cell layer can differentiate into the transitional portion of the follicle and anagen hair.
The nature of clear cell acanthoma has not been clarified, although many hypotheses have been proposed, including a benign neoplasm derived from epidermis or the acrosyringium, or a non-specific dermatosis. In this study, seven cases of clear cell acanthoma were analysed by immunohistochemical techniques, using various monoclonal antikeratin antibodies, and antibodies against filaggrin, involucrin and epithelial membrane antigen. Different immunoreactivities were noted between clear cell acanthoma and a normal eccrine gland, including the acrosyringium. Immunoreactivities of clear cell acanthoma were almost identical to those of normal epidermis, although some antibodies gave a different staining pattern between clear cell acanthoma and normal epidermis. The expression of cytokeratins in psoriatic epidermis has been reported to change as a result of abnormal differentiation or maturation. Clear cell acanthoma showed a similar staining pattern to inflammatory dermatoses such as psoriasis vulgaris, lichen planus and discoid lupus erythematosus. We speculate that clear cell acanthoma is a localized form of inflammatory dermatosis rather than a neoplasm.
An histologically typical clear cell acanthoma was identified forming a cystic structure. The finding of clear cell acanthoma within a cyst is histologically unique.
Clear cell acanthoma (CCA) is a usually solitary benign epidermal-tumor. Multiple lesions are infrequently reported.
A case of multiple eruptive CCA is reported in which a successful cryotherapic treatment was performed.
A 59-year-old man with varicose veins and dry skin presented with 17 eruptive asymptomatic papulo-nodular lesions on both legs.
Two lesions were excised with a histologically confirmed diagnosis of CCA. Other lesions were treated with liquid nitrogen. All the lesions resolved with minimal residual scarring after three to four treatments.
Multiple CCA is a rare condition; fewer than 20 cases having been described. The presence of associated conditions like dry skin and varicose veins are discussed. Because of the tendency of persistence of the lesions, cryotherapic treatment may be a useful method of therapy.
Clear cell acanthoma is usually a solitary lesion. We report a patient with multiple lesions demonstrating the typical clinical and histological features of clear cell acanthoma, which responded well to treatment with liquid nitrogen.
This is a report on a 38-year-old female, suffering from over 100 solid papules arising on her legs, arms and trunk during the past 10 years. The histology shows the typical feature of clear-cell acanthoma (CCA). Extensive investigations did not reveal any extracutaneous abnormalities. This case is exceptional because of the high number of hamartomatous CCA which exceeds the maximal number of about 20 seen in multiple CCA so far and therefore is referred to as eruptive hamartomatous CCA.
We present five cases of macroscopically pigmented clear cell acanthomas. Masson-Fontana silver stain revealed dendritic melanocytes containing melanin granules in large numbers interspersed among the tumoral keratinocytes. The dendritic cells expressed S-100 protein. Electromicroscopy, performed on one pigmented clear cell acanthoma, showed melanosomes in large numbers in the dendrites of melanocytes; whereas only a few melanosomes were found in the adjacent keratinocytes, indicating a disturbed melanin transfer. We propose the name "pigmented clear cell acanthoma" for this variant of Degos' acanthoma.
Clear cell acanthoma (CCA) is a benign epidermal tumour with distinctive and uniform clinical and histological features. Although solitary lesions are the rule, some cases of multiple CCA, rarely with more than 10 lesions, have been previously reported. Only 22 cases of multiple CCA have been described in the English literature to date. A healthy 32-year-old woman is reported, with approximately 400 asymptomatic rounded papules, on the upper and lower extremities. Multiple skin biopsies showed the typical histological pictures of CCA. This case appears unusual because of the presence of numerous lesions scattered on the upper and lower extremities. For this reason it could be classified as disseminated eruptive CCA.
A brief discussion of the subject.
The purpose of the work to be described.
How the work was performed.
The outcome of the work.
The conclusion that can be reached based on the work described.
A 33-year-old Japanese woman presented with a black papule on a pigmented lesion which had been on her right thigh since her early childhood. A hematoxylin-eosin-stained section revealed a sharply demarcated, acanthotic epidermis composed of enlarged clear cells, which stained positively for epithelial membrane antigen and negatively for carcinoembryonic antigen. With antikeratin antibodies, the tumor cells stained for AE1 and AE3, but did not stain for CAM5.2. They contained abundant glycogen. Histologically, we diagnosed the case as a clear cell acanthoma which developed in the pre-existing epidermal nevus. This is the second such case in the literature.
We report on a case of clear cell acanthoma that developed above a preexisting melanocytic nevus. Although melanocytic nevi can be complicated by the presence of several different types of epithelial or appendageal tumors, there have been no reported case of clear cell acanthoma combined with a nevus. Interestingly, in this case the clear cell acanthoma had a polypoid configuration, an unusual finding.
