Update on the Diagnosis and Management of Desmoplastic Melanoma. / Actualización en el diagnóstico y manejo del melanoma desmoplásico.

Desmoplastic melanoma (DM) accounts for 0.4% to 4% of all melanomas. These skin tumors are mainly formed by amelanotic spindled melanocytes immersed in an abundant collagen stroma and are classified as pure when the desmoplastic component accounts for at least 90% of the invasive tumor and as mixed or combined otherwise. DMs are more common in men (male to female ratio, 1.7 to 2:1), and the mean age at diagnosis is 66 to 69 years. The tumors tend to occur in chronically sun-exposed areas, often in association with lentigo maligna, and are difficult to recognize because they can resemble a scar, presenting as a firm, unpigmented papule or plaque with poorly defined borders. DMs also have a strong tendency to recur locally, and pure variants rarely spread to the lymph nodes. Nonetheless, recently published series suggest that patients with DM have a similar prognosis to those with nondesmoplastic melanoma of the same thickness. The clinical management of DM varies in certain aspects from that of other melanomas and is reviewed in this article.

Wolf's isotopic response: a series of 9 cases.

INTRODUCTION: The term Wolf's isotopic response refers to the appearance of a new skin disease at the site of an already healed, unrelated disease. In most cases, the initial disease is herpes zoster. Different diseases may subsequently develop on the same site. The most common isotopic responses are granulomatous and lichenoid reactions, infiltrations of hematologic diseases, skin tumors, and infections. The pathogenesis of these skin reactions is unknown. It has been suggested that viral infection may alter local skin immunity; this would favor hyperreactivity, leading to inflammatory processes, or local immunosuppression, leading to tumor infiltrations or infections. MATERIALS AND METHODS: We performed a retrospective study of 9 patients diagnosed with Wolf's isotopic response in the dermatology department of Hospital Donostia in San Sebastian, Spain. Five patients had B-cell chronic lymphocytic leukemia, 2 had a non-Hodgkin lymphoma, and 1 had ovarian carcinoma. RESULTS: The initial disease was herpes zoster in 7 cases, and chickenpox and herpes simplex in the other 2 cases. The second disease was granulomatous dermatitis in 4 cases, lichenoid dermatitis in 2 cases, infiltration by B-cell chronic lymphatic leukemia in 2 cases, and infiltration by systemic non-Hodgkin lymphoma in 1 case. In the last case, the skin lesions were the first sign of the lymphoma. CONCLUSIONS: We highlight the need to biopsy these second lesions in order to rule out tumor infiltrations, which were more frequent than expected in our series.