Ronald M. Zuker's research while affiliated with Queen's University and other places

Publications (204)

Article
The success of conjoined twin separation has increased since the 1950s, notwithstanding the numerous technical and physiological challenges encountered in such procedures. Together with improvements in our understanding of conjoined twin physiology and the accumulation of surgical expertise, technological advances have largely paralleled the improv...
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Background: Conjoined twinning is a rare medical phenomenon, and numerous challenges remain with respect to surgical separation and reconstruction. The purpose of this study is to present a detailed discussion of the authors' institutional experience with eight conjoined twin separations over the past three decades, focusing on challenges and less...
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Background: Craniofacial microsomia is associated with maxillomandibular hypoplasia, microtia, soft-tissue deficiency, and variable severity of cranial nerve dysfunction, most often of the facial nerve. This study evaluated the incidence of patients with craniofacial microsomia and facial paralysis and their outcomes after free functioning muscle...
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A consortium of global cleft professionals, predominantly from low- and middle-income countries, identified adaptations to cleft care protocols during and after COVID-19 as a priority learning area of need. A multidisciplinary international working group met on a videoconferencing platform in a multi-staged process to make consensus recommendation...
Chapter
Facial paralysis is a complex condition that can affect a patient’s function, comfort, and psychosocial well-being. Great strides have been made in the techniques of reconstruction, especially with microsurgery, innovation in concepts with nerve transfers and muscle grafts, and the application of positive laboratory results to the clinical setting....
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Cross-face nerve grafting enables the reanimation of the contralateral hemiface in unilateral facial palsy and may recover a spontaneous smile. This chapter discusses various clinically applicable strategies to increase the chances for good functional outcomes by maintaining the viability of the neural pathway and target muscle, increasing the numb...
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Facial paralysis may result in significant functional, aesthetic, and psychological morbidity. Möbius syndrome is a form of bilateral congenital facial paralysis that is particularly difficult to treat owing to the lack of readily available donor nerves, particularly in the upper face. In this study we evaluate the feasibility of using the deep tem...
Chapter
Children with facial paralysis face challenges which are both functional as well as psychosocial in nature. Numerous methods have been employed to restore facial movement using various regional and distant muscle transfers. Two-stage facial reanimation is a reliable technique for restoring midface motion in patients with unilateral facial paralysis...
Chapter
The cornea is among the most densely innervated structures in the human body and corneal innervation is indispensable for maintaining the ocular surface health. The acquired loss or congenital absence of corneal nerve fibers result in neurotrophic keratopathy. This degenerative disease of the anesthetic cornea is characterized by progressive cornea...
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Facial palsy can cause impairment of eye closure and affect blink, ocular health, communication, and aesthetics. Dynamic surgical procedures can restore eye closure in patients with decreased facial nerve function. There are no standardized measures of voluntary and spontaneous eye closure that are used to evaluate the outcomes of blink restoration...
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Purpose of Review Since 1998, over 120 upper extremity transplants have been successfully performed around the world; however, the field of vascularized composite allotransplantation (VCA) continues to face various medical challenges and ethical controversies. This article summarizes the worldwide experience with transplantation of vascularized com...
Article
Objective To test the feasibility of implementing a high-fidelity cleft palate simulator during a workshop in Santiago, Chile, using a novel video endoscope to assess technical performance. Design Sixteen cleft surgeons from South America participated in a 2-day cleft training workshop. All 16 participants performed a simulated repair, and 13 of t...
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Introduction: Facial paralysis impairs the mimetic functions of the facial musculature. In pediatric patients, free functioning muscle transfer neurotized with an intact contralateral facial nerve is the gold standard for smile reanimation. In response to requests from families of children with facial paralysis, the Division of Plastic and Reconst...
Article
Background: Smiling is a fundamental component of social interactions. Significant challenges arise for patients with facial palsy. One of the key procedures for dynamic smile restoration is the microneurovascular transfer of a gracilis muscle. We aimed to assess the effectiveness and safety of dynamic smile reanimation surgery using the free grac...
Article
Background: Möbius syndrome is a complex congenital disorder of unclear cause involving multiple cranial nerves and typically presenting with bilateral facial and abducens nerves palsies. At The Hospital for Sick Children, Toronto, Ontario, Canada, microneurovascular transfer of free-muscle transplant is the procedure of choice for midfacial anima...
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Aim To report clinical outcomes and evidence of corneal innervation in patients with neurotrophic keratopathy (NK) treated with minimally invasive corneal neurotisation (MICN) using a sural nerve graft and donor sensory nerves from the face. Methods Patients undergoing MICN at The Hospital for Sick Children, Toronto, Canada were prospectively recr...
Article
Background: Corneal denervation can lead to opacification and blindness. A new treatment technique, surgical corneal neurotization, transfers healthy donor nerve, (most commonly contralateral supratrochlear or supraorbital) to the affected limbus to prevent corneal destruction and improve healing potential of the cornea following insult. We examin...
Article
Background: Living donor liver transplantation (LDLT) is an important strategy of procuring segmental liver allografts for pediatric patients with liver failure, as suitably sized whole donor organs are scarce. Early pediatric LDLT experience was associated with high rates of hepatic artery thrombosis, graft loss, and mortality. Collaboration with...
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Bilateral facial paralysis is a rare entity that occurs in both pediatric and adult patients and can have congenital or acquired causes. When paralysis does not resolve with conservative or medical management, surgical intervention may be indicated. This article presents the authors' preferred technique for facial reanimation in patients with bilat...
Article
Background: The sural nerve is a common donor site for nerve reconstruction. The only study describing outcomes in paediatric patients was following bilateral sural nerve harvest before the age of 1 year. Bilateral nerve harvest at such a young age may limit patients' ability to perceive a sensory difference. The objective of this study was to und...
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Background: Gracilis muscle transplant is the standard of care for smile reconstruction in children with Möbius syndrome. The authors describe the long-term clinical efficacy, durability, and psychosocial impact of this approach at a mean follow-up of 20 years. Methods: Patients with Möbius syndrome who underwent gracilis muscle transfer between...
Article
Objectives: Paediatric coronary artery bypass grafting is indicated in cases of clinically significant and symptomatic coronary stenosis, with frequent complications occurring in the perioperative period. To reduce complications and improve outcomes of these procedures, surgical microscopes have been used at our centre with the anastomosis perform...
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Purpose: To document the presence and location of new sensory nerve fibers after corneal neurotization using in vivo confocal microscopy (IVCM) in 2 patients with neurotrophic keratopathy (NK). Methods: Two patients with unilateral advanced NK received corneal neurotization to surgically reinnervate the cornea. IVCM was used to identify subbasal...
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Background: Forearm compartment syndrome in the pediatric population can lead to severe functional disability. Although it is known that earlier presentation with decompression leads to better outcomes, it is not known when presentation post-injury leads to significant loss of function requiring microsurgical intervention. Aim: To describe the r...
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Full-text available
Smiling is an important aspect of emotional expression and social interaction, leaving facial palsy patients with impaired social functioning and decreased overall quality of life. Although there are several techniques available for facial reanimation, staged facial reanimation using donor nerve branches from the contralateral, functioning facial n...
Chapter
Vascularized Composite Allotransplantation (VCA) enables improved function and quality of life for those who have lost anatomical parts such as a limb and the relief of profound suffering for those with severe facial disfiguration. VCA differs from vital organ transplantation in two important ways: (1) these transplants are not necessary for recipi...
Article
Facial paralysis in children is a disabling functional and aesthetic issue. In cases where recovery is not expected, there are numerous options for reconstruction of the midface "smile." At the Hospital for Sick Children in Toronto, Canada, we have been using a free functional gracilis muscle transfer. In this article, we review the technical detai...
Article
We illustrate the case of a brachial pseudoaneurysm in a 32-week preterm baby male who presented with a large pulsatile mass in the right antecubital fossa, with no clear aetiologic factor. The management of this type of lesion has been controversial and based mainly on case reports. In this case, after obtaining partial response with two thrombin...
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Pediatric coronary bypass grafting requires special technical consideration and microsurgical techniques, including appropriately fine instruments, 10-0 or 11-0 microsutures, and repair under an operating microscope. At The Hospital for Sick Children, the Divisions of Cardiac and Plastic and Reconstructive Surgery have utilized the expertise of bot...
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Purpose of review: In this review article, aimed at those likely to encounter but relatively unfamiliar with paediatric facial paralysis, we summarize reconstructive options in its surgical management. Recent findings: The article looks at static and dynamic reconstructions available to address the problems encountered in the different anatomica...
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Intravascular pyogenic granuloma is a rare tumour, with approximately 30 cases presented previously in the literature. It most commonly occurs in the veins of the head and neck and upper extremity in middle-age patients. There is a paucity of reports detailing this lesion the pediatric literature. A case involving a 14-year-old boy with an intraven...
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Although treating facial palsy is considered debilitating for patients, trigeminal nerve palsy and sensory deficits of the face are overlooked components of disability. Complete anesthesia leaves patients susceptible to occult injury, and facial sensation is an important component of interaction and activities of daily living. Sensory reconstructio...
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Proximal forearm replantation presents with multiple challenges. In this paper, we present the unique advantages of transplantation at the level of proximal forearm and contrast this to replantation. We describe the rationale for transplantation following below elbow amputation: the bone level allows fixation and preservation of the functioning elb...
Article
Facial paralysis can have significant functional, psychological and aesthetic concerns that alter the lives of our patients. These effects can be functional, affecting the eye, nose and mouth, or aesthetic, affecting the symmetry of the face and particularly the mimetic function of smile. Several reanimation procedures have been described to addres...
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Botulinum toxin A has been described as an effective adjunct treatment for achieving symmetry in adults with facial paralysis. Few investigators have described the use of botulinum toxin A in pediatric patients with facial paralysis. To present our preliminary experience with botulinum toxin A in pediatric patients presenting with asymmetry of the...
Article
Corneal anesthesia is a debilitating condition which can ultimately lead to blindness from repetitive corneal injury and scarring. We have developed a minimally invasive technique for corneal re-innervation that we have used with excellent results in ten eyes. This article and accompanying video describes the relevant anatomy and demonstrates the t...
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Free functional muscle transfer to the face is a standard of facial animation. The contralateral facial nerve, via a cross-face nerve graft, provides spontaneous innervation for the transferred muscle, but is not universally available and has additional shortcomings. The motor nerve to the masseter provides an alternative innervation source. In thi...
Article
Importance Corneal anesthesia is recalcitrant to conventional treatment and can lead to permanent visual loss.Objective To assess the outcomes of a novel sensory reconstructive technique for the treatment of corneal anesthesia.Design, Setting, and Participants This prospective study evaluating a new technique was conducted at a tertiary referral...
Article
Background: Limb salvage operations in patients with bony oncologic defects carry technical challenges and may require long recoveries. This study aimed to evaluate functional outcomes, donor-site morbidity, and complications in lower limb bony oncologic defects reconstructed with vascularized fibula flaps in children. Methods: The authors perfo...
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Facial transplantation is becoming increasingly accepted as a method of reconstructing otherwise unreconstructable adult faces. As this modality is made more available, we must turn our attention to pediatric patients who may benefit from facial transplantation. In the current article, the authors present and briefly examine the most pressing ethic...
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Facial transplantation is becoming increasingly accepted as a method of reconstructing otherwise unreconstructable adult faces. As this modality is made more available, we must turn our attention to pediatric patients who may benefit from facial transplantation. In the current article, the authors present and briefly examine the most pressing ethic...
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Hand fractures represent a leading cause of morbidity in children. However, little information exists correlating the mechanisms and environment of injury with outcomes and treatments. We examine the demographics, etiology, anatomic location, mechanism, and management of pediatric hand fractures in our center's hand unit. We conducted a prospective...
Article
Congenital melanocytic nevi remain a subject of controversy with respect to risk of malignant transformation and recommended management. Recent studies indicate a lower malignant risk (0.7 to 2.9 percent) than had previously been estimated. Surgery has not been proven to reduce malignant risk or improve quality of life, and may result in undesirabl...
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In vascularized composite allotransplantation, multiple types of tissue are transferred from donor to recipient as a single functional unit. This technique has been performed for upper extremity, face, and abdominal wall transplants, among many others. To review the existing cases of face and upper extremity vascularized composite allotransplantati...
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Introduction: Muscle transfer is used to restore function typically using a single vector of contraction. Although its use with two independently functional muscular units has been employed, in order to refine this concept we endeavoured to detail the intramuscular anatomy of gracilis, a muscle commonly used for transfer. A novel method to capture...
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Background: Despite generally excellent success with vascularized composite allotransplantation at many body sites over the past two decades, vascularized composite allotransplantation as a treatment modality for lower extremity amputees has not yet been fully embraced. Methods: The authors summarize the anticipated benefits of lower limb allotr...
Article
: The anatomy of the facial nerve and its branches has been well documented. The course of the extratemporal facial nerve, its anatomical planes, and the surface landmarks of the temporal division and marginal mandibular division are well known. However, the surface landmark of the middle division of the facial nerve has not been studied to date. :...
Article
The motor nerve to the masseter muscle is increasingly being used for facial reanimation procedures. However, many surgeons have been reluctant to use this versatile source of axons because of difficulty in locating it intraoperatively. In this study we conducted a detailed assessment of its gross and microscopic anatomy and develop a simple, relia...
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Vascularized composite allotransplantation as a viable reconstructive option is gaining recognition and new cases are being reported with increasing frequency including hand, face and laryngeal transplantation. However, only one successful complete lower limb transplantation has been reported to date, in which a functioning limb from one ischiopagu...
Article
Children are prone to developing moderate to severe Volkmann ischemic contracture following a supracondylar fracture of the humerus or its treatment. Given the variable extent of forearm muscle damage, tendon transfers and tenodeses are often unavailable. To address these contractures, intensive hand therapy and a free functioning muscle transfer a...
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Pediatric hand and wrist ganglia seem to have different epidemiological characteristics than those of adults - a majority are found on the volar aspect of the hands and wrists of patients younger than 10 years of age. To determine the epidemiology, etiological factors, clinical presentation, treatment and outcome of patients with ganglion cysts at...
Article
Although benign and metastatic tumors occur in children, primary malignant skin tumors are uncommon in the pediatric population. In this study, the authors aimed to determine the incidence, risk factors, treatment, reconstruction details, and outcome of malignant skin tumors occurring in pediatric patients at the Hospital for Sick Children. The ele...
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Early experience with living donor liver transplantation (LDLT) was often complicated by hepatic artery thrombosis (HAT), a devastating complication resulting in graft loss. Attempting to reduce the incidence of HAT, we undertook a retrospective review of all children at our institution undergoing LDLT between March 2000 and August 2007, with the h...
Article
Juvenile xanthogranuloma is a relatively uncommon, benign histiocytic proliferative disorder. A case of juvenile xanthogranuloma in a 13-month-old girl with an unusual clinical form is described. She presented with a yellow-red projecting nodule over the helical rim of her right ear. The lesion was histologically diagnosed as juvenile xanthogranulo...
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Current pediatric burn care has resulted in survival being the expectation for most children. Composite tissue allotransplantation in the form of face or hand transplantation may present opportunities for reconstructive surgery of patients with burns. The present paper addresses the question "Could facial transplantation be of therapeutic benefit i...
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To examine the prevalence of speech, language, hearing, and dental problems in children with an initial diagnosis of isolated cleft lip only (CL), for which evidence-based practice can be developed. Retrospective chart review of 95 patients with cleft lip (age range, 2.8 to 3.7 years; mean, 3.1 years). Speech and language impairment was documented...
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The present case report describes a juvenile xanthogranuloma in a five-month-old girl. A circumscribed papule was located below the right nasal ala and above the right vermilion border. The lesion was histologically diagnosed as a juvenile xanthogranuloma after surgical resection of the mass. Juvenile xanthogranuloma is an uncommon diagnosis, with...
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The use of the nasoalveolar molding technique (NAM) aims to reduce passively the width of the alveolar gap, while improving the AP discrepancy but also focusing on the nose. We developed a within-subjects study in which 11 infants with unilateral lip deformity and varying degrees of alveolar gaps were treated by NAM. Patients included in the study...
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Abdominal wall reconstruction in omphalopagus twins poses a difficult reconstructive challenge, as separation often results in a large abdominal wall defect. A number of options are available for closure, including tissue flaps, expanders and patches made of foreign material. Surgisis is a new biodegradable small intestine scaffolding substrate tha...
Chapter
Facial paralysis produces significant functional, aesthetic, and emotional problems. Craniofacial surgeons may find the management of facial paralysis confusing, partly because of the myriad of surgical options presented in the literature. The use of an algorithmic approach in facial paralysis allows the surgeon to evaluate patients in a systematic...
Article
Functioning free muscle transfer to the upper extremity is an extremely complex and difficult procedure. It is useful only in selected cases that require significant skeletal muscle replacement and fulfill stringent criteria. The operation itself is performed by means of a two-team approach. Attention to detail is paramount if success is to be achi...
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Amniotic band syndrome is an uncommon clinical entity with a spectrum of presentation including constriction rings, syndactyly, amputations, and spontaneous abortion. The bands themselves are not present at the time of birth. This has created controversy regarding the pathogenesis of the disorder. The unusual case of a neonate with a persistent ban...
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Extraskeletal Ewing's sarcoma (EES) is a rare, soft tissue, malignant neoplasm histologically similar to skeletal Ewing's sarcoma. It occurs mainly in adolescents and young adults, and affects extremities in 36% of cases and central locations (commonly paravertebral regions) in the remainder. The differential diagnosis includes other small, blue, r...
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Pilomatricoma (calcifying epithelioma of Malherbe) is a common skin neoplasm in the pediatric population that is often misdiagnosed as other skin conditions or tumours. The objective of the present retrospective study was to review the clinical and histopathological presentation of this neoplasm in children. The records of the pathology department...
Chapter
Limb transplantation is now a clinical reality. The success of upper-limb transplantation prompted us at the Hospital for Sick Children in Toronto, Canada, to apply the concept to the lower extremity. The hindquarter of a failing conjoined twin was transplanted to her healthy sister at the time of separation. Appropriate bony, muscular, vascular an...
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The microneurovascular transfer of a free muscle transplant is the procedure of choice for facial animation in a child with facial paralysis. One of the critical factors of this procedure is the selection of a motor nerve to innervate the transplanted muscle. From 1989 to 1999, 166 free segmental gracilis muscle transfers were performed in 121 chil...
Article
Composite tissue transplantation has emerged as a viable alternative to prosthetics and complex reconstructive surgery. Thus far it is reserved for cases which cannot be effectively reconstructed and where it offers some benefits over prostheses. It has been used in the upper extremity with encouraging results and, most recently, in the face. This...
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Thirty-four free tissue transfers for reconstruction of various tissue defects to the lower extremities were performed in 32 children over a 20-year period (1980 to 1999). Patient ages ranged from 3 to 19 years (mean: 10.8 years). Four donor sites were used: gracilis muscle, latissimus dorsi muscle, iliac crest osteocutaneous, and vascularized fibu...
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The management of congenital melanocytic nevi is controversial. The authors describe their management of a congenital nevus covering the breast and abdomen of a one-month-old girl over a 16-year period. To prevent damage to the developing breast, a staged approach was used. The nevus over the abdomen was resected first at six years of age and the r...
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The presence of deep pigmentation in a giant congenital nevus makes its complete removal very difficult and should be taken into consideration when planning for treatment. A clinical case in which the pigmented lesion was found to extend deep into the muscle fascia is described. The lesion was surgically removed with an acceptable functional and ae...
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Iatrogenic fetal injury during cesarean delivery is a serious but underreported complication. A distal iatrogenic amputation of a digit occurred during a cesarean delivery. Obstetricians should be aware of this potential complication.
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Moebius sequence is a rare congenital absence of the sixth and seventh cranial nerves, although there may be additional congenital cranial neuropathies. Developmental delay, cardiac and musculoskeletal abnormalities may also co-exist. Oro-facial manifestations include bilateral facial nerve palsy resulting in a mask like facies, drooling, incomplet...
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Full-text available
Background Moebius sequence is a rare congenital absence of the sixth and seventh cranial nerves, although there may be additional congenital cranial neuropathies. Developmental delay, cardiac and musculoskeletal abnormalities may also coexist. Oro-facial manifestations include bilateral facial nerve palsy resulting in a mask like facies, drooling,...
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The treatment of congenital facial nevi is often difficult and challenging. Previous authors have reported their techniques, results, and complications when treating these lesions. Our objectives are to simplify the treatment planning by subdividing the lesions with a new classification and using this to formulate a surgical algorithm. One hundred...
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Cutaneous ganglioneuroma has only occasionally been reported in the literature. Cutaneous ganglioneuroma is seen even more rarely in association with a giant congenital nevus. Differential diagnosis includes malignancies, especially melanoma and metastatic neuroblastoma. It is essential to rule out malignancy in a solid lesion within a congenital n...
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Congenital epulis is a rare benign hamartoma of the alveolar ridge found in the newborn. The clinical characteristics of this lesion show some variability, and opinion of its pathogenesis lacks consensus. Congenital epulis can cause feeding or respiratory compromise. A case report and review of the literature is presented. The diagnosis, pathology,...