Faculty Bibliography

BACKGROUND: Although the majority of melanomas demonstrate high rates of mutations in B-RAF or N-RAS that result in constitutive activation of the mitogen-activated protein kinase-signaling pathway, emerging data suggest molecular differences among melanoma subtypes. In this study, the authors evaluated the contribution of B-RAF and N-RAS mutations to the pathogenesis of Spitzoid melanomas. METHODS: In total, 33 Spitzoid melanomas were analyzed for clinical and pathologic characteristics as well as for hot-spot mutations in the B-RAF and N-RAS genes. In the majority of patients (28 of 33 melanomas), the tumors were confined to the skin with no evidence of metastasis (average follow-up, 32.5 mos). There were five metastasizing melanomas (5 of 33 tumors) with regional or systemic spread. RESULTS: Of 33 Spitzoid melanomas, only 1 showed the V600E mutation in the B-RAF gene (1 of 33 tumors; 3%). It was noteworthy that none of the metastatic Spitzoid melanomas (0 of 5 tumors; 0%), of which 2 resulted in fatal outcomes, demonstrated mutations in B-RAF or N-RAS. CONCLUSIONS: In contrast to the majority of cutaneous melanomas, activating hot-spot mutations in B-RAF or N-RAS were not involved in the pathogenesis of Spitzoid melanoma. These data suggested that Spitzoid melanoma is a distinct form of melanoma with unknown genes and/or signaling pathways involved in its development.

A 58-year-old woman with linear porokeratosis involving the right hand and arm had distal digital narrowing and nail dystrophy with radiographic changes. Whereas isolated cases of bone resorption and flexion deformities with porokeratosis of Mibelli are known to occur, to our knowledge, bony abnormalities in association with linear porokeratosis have not been reported.

Dermatofibrosarcoma protuberans (DFSP) is an uncommon tumor with its onset typically in the second to fifth decades of life. It most commonly presents on the trunk, and recent cytogenetic studies suggest a neural origin. A case presentation and review of the recent literature on the diagnosis, differential diagnosis, and treatment of DFSP is presented.

BACKGROUND: Subungual melanoma is a relatively rare disease with reported incidence between 0.7% to 3.5% of all melanoma cases in the general population. Unlike the significant improvement in the diagnosis of cutaneous melanoma, the diagnosis of subungual melanoma has shown little, if any, improvement over the years. The widespread adoption of the ABCDs of cutaneous melanoma has helped increase public and physician awareness, and thus helped increase the early detection of cutaneous melanoma; the same criteria cannot be applied to the examination of the nail pigmentation. OBJECTIVE: We reviewed the world literature on subungual melanoma and arranged the available information into a system for the identification of subungual melanoma. This system has to be thorough, easy to remember, and easy to apply by both physician and lay public. A case to illustrate the delayed diagnosis often encountered in the current evaluation of nail melanoma is presented. METHODS: A thorough review of the world literature on subungual melanoma was undertaken. The important findings of various studies and case reports were compared among themselves and the salient features were summarized. The information was then categorized under the easily recalled letters of the alphabet, ABCD, that have already become associated with melanoma. RESULTS: The most salient features of subungual melanoma can be summarized according to the newly devised criteria that may be categorized under the first letters of the alphabet, namely ABCDEF of subungual melanoma. In this system A stands for a ge (peak incidence being in the 5th to 7th decades of life and African Americans, Asians, and native Americans in whom subungual melanoma accounts for up to one third of all melanoma cases. B stands for brown to black b and with breadth of 3 mm or more and variegated borders. C stands for change in the nail band or lack of change in the nail morphology despite, presumably, adequate treatment. D stands for the digit most commonly involved; E stands for extension of the pigment onto the proximal and/or lateral nailfold (ie, Hutchinson's sign); and F stands for family or personal history of dysplastic nevus or melanoma. CONCLUSION: Although each letter of the alphabet of subungual melanoma is important, one must use all the letters together to improve early detection and thus survival of subungual melanoma. Still, as with cutaneous melanoma, the absolute diagnosis of subungual melanoma is made by means of a biopsy