Subungual melanoma: A study of 124 cases highlighting features of early lesions, potential pitfalls in diagnosis, and guidelines for histologic reporting
ABSTRACT Subungual melanoma (SUM) is an uncommon variant of melanoma that is often difficult to diagnose, both clinically and pathologically. In an attempt to provide pathologic clues to diagnosis, especially in early lesions or small biopsies, and to provide practical advice to pathologists in reporting, the clinicopathologic features of 124 cases of SUM were reviewed, the largest series reported to date. The features of 28 cases of subungual melanoma in situ (MIS), comprising 4 cases of MIS and 24 cases where areas of MIS were present adjacent to dermal-invasive SUMs, were compared with those of a similar number of acral nevi to identify useful distinguishing features. The median age of the patients was 59 years and the most common site was the great toe (24%). Nine percent of cases were AJCC stage 0, 14% were stage I, 41% were stage II, 32% were stage III, and 4% were stage IV at initial diagnosis. The commonest histogenetic subtype was acral lentiginous (66%), followed by nodular (25%) and desmoplastic (7%). The majority of tumors were locally advanced at presentation with 79% being Clark level IV or V. The median Breslow thickness was 3.2 mm. The median mitotic rate was 3 per mm and 33% of cases demonstrated primary tumor ulceration. Seven of 29 patients (24%) who underwent a sentinel lymph node biopsy had nodal disease. Multivariate Cox-regression analysis showed higher disease stage to be the only significant predictor of shortened survival. In comparison to acral nevi, MIS more frequently showed lack of circumscription, a prominent lentiginous growth pattern, predominance of single cells over nests, moderate-to-severe cytologic atypia, a dense and haphazard pagetoid intraepidermal spread of melanocytes, and the presence of junctional/subjunctional lymphocytes ("tumor infiltrating lymphocytes"). Tumor infiltrating lymphocytes have not been highlighted previously as a feature of subungual MIS and represent a useful diagnostic clue. Guidelines for the reporting of SUMs are also presented. Knowledge and recognition of the pathologic features of SUMs and the important features that distinguish them from nevi should reduce the frequency of misdiagnosis.
Article: Longitudinal melanonychias[Show abstract] [Hide abstract]
ABSTRACT: Melanonychia is black or brown pigmentation that appears in the fingernails and toenails. The pigment can come from exogenous sources, such as bacteria or fungal infection, tar, or blood. Endogenous causes include aberrant melanin production in the nail bed, resulting in a longitudinal presentation. Melanonychia can indicate the presence of cancerous growths, as well as infection. Diagnostic measures, including dermatoscopy, biopsy, and histopathology, can determine the cause and direct the course of treatment. Malignant lesions should be excised, and underlying infections should be addressed with antibiotics or antifungals. Benign lesions and hyperpigmentation may benefit from a wait-and-see approach.Clinics in dermatology 09/2013; 31(5):594-601. DOI:10.1016/j.clindermatol.2013.06.007 · 1.93 Impact Factor
Article: Nail tumors[Show abstract] [Hide abstract]
ABSTRACT: Most neoplasms of the nail apparatus have different clinical appearances, courses, and biological behaviors as compared with similar tumors located elsewhere on the skin. Some of these tumors are unique to the nail, such as onychomatricoma. As a general rule, benign lesions respect the general architecture of the nail apparatus, whereas malignant ones are destructive. Our review covers the most common nail tumors, from benign ones to the most frequent nail malignancy, the squamous cell carcinoma, which actually is the greatest simulator. We will also discuss new approaches to the diagnosis and treatment of melanoma of the nail apparatus. Physicians should be aware of these conditions and their management.Clinics in dermatology 09/2013; 31(5):602-617. DOI:10.1016/j.clindermatol.2013.06.014 · 1.93 Impact Factor
Article: Acral Lentiginous Melanoma[Show abstract] [Hide abstract]
ABSTRACT: Between 1958 and 1990, 82 patients with acral lentiginous melanoma were treated by the Tulane Surgical Service with regional perfusion, excision of lesion, and lymph node dissection. The patient group comprised 27 white men, 29 white women, 18 black men, and 8 black women, with an average age of 61 years. More foot lesions than hand lesions were reported, and all the lack men had foot lesions. In stage I patients, overall 5-year survival rates were 65% at 5 years and 44% at 10 years, with differences by race and gender. The black men did poorest, with a 13% 10-year survival rate. Survival rates were worse with increasing disease stage when calculated using univariate analysis. The 5-year survival rate of all patients with stage III and stage IV disease was 26%. A multivariate analysis was performed in 78 of 82 patients in whom all variables of Clark's level, age, race, stage, and sex were known. A strong relationship was observed between decreasing survival time and increasing Clark's level, with stage of marginal significance. In a multivariate analysis of patients with stage I disease, an increasing level of invasion was found to be significant, with a trend for a relationship to thickness. A trend toward decreased survival time was observed in men and blacks.The American Journal of Surgery 08/1993; 166(1):64-7. DOI:10.1016/S0002-9610(05)80586-0 · 2.41 Impact Factor