Desmoplastic melanoma presenting as primary alopecia neoplastica: a report of two cases

Abstract

Desmoplastic melanoma is an uncommon form of melanoma characterized by atypical spindled melanocytes and abundant collagen deposition. It typically presents in sun-damaged skin of the elderly as an amelanotic, indurated lesion. It has a higher tendency for local recurrence but lower risk of lymph node metastasis vs. conventional malignant melanoma. We report two cases in women aged 59 and 66 who presented with small scalp lesions clinically suggestive of alopecia. The differential diagnosis included alopecia areata, lupus erythematosus and lichen planopilaris. Biopsies performed according to alopecia protocol were reviewed at our institutions. Biopsies revealed atypical spindled and nested epithelioid melanocytes set in a sclerotic dermis with scattered lymphoid aggregates and immunohistochemical expression of S100 protein, features diagnostic of combined desmoplastic melanoma. Wide local excision with skin graft was performed on the older patient. Excision showed combined desmoplastic melanoma with a Breslow thickness of 8.5 mm with melanoma in situ identified in the adjacent epidermis. The other patient sought treatment elsewhere and was lost to follow up. These cases illustrate desmoplastic melanoma as an unusual etiology and dangerous clinical pitfall in patients with scar-like alopecia. To the authors' knowledge, these represent the second and third reported cases of desmoplastic melanoma presenting as primary alopecia neoplastica.

Desmoplastic melanoma presenting as an alopecic patch in a young patient

“…The first identified a 50-year-old man with a localized erythematous patch of hair loss on the left frontal scalp. 7 Three cases presented with alopecic patches of a few months’ duration 8 , 9 ; the differential included alopecia areata, discoid systemic lupus erythematosus, and lichen planus. After failure to respond to standard therapy, 2 patients underwent biopsy followed by wide local excision of the primary lesion.…”

“…After failure to respond to standard therapy, 2 patients underwent biopsy followed by wide local excision of the primary lesion. 7 , 8 A third patient sought surgical treatment at an outside facility but was lost to follow-up, 8 while the fourth patient underwent radiation therapy vs surgery due to lesion size. 9 A few patients experienced multiple recurrences and even neurotropism in the first reported case with involvement of the trigeminal nerve, emphasizing risk of neurologic involvement.…”

“…Presentation as an alopecic patch is an uncommon scenario, with only 4 previous reported cases to the authors’ knowledge. 7 , 8 , 9 , 10 Here, we report a unique case of DM presenting as an alopecic patch on the scalp of a young male unresponsive to topical steroids.…”

Primary Alopecia Neoplastica: A Novel Case Report and Literature Review

“…It was postulated that AN resulted from direct fibrosis or release of cytokines from infiltrating tumor cells [66]. Another report presented 2 cases of primary DMM resulting in primary AN [65]. In all 3 of these cases (Table 1), the patients presented with a nonpigmented patch with reduced follicular density or no intact follicles.…”

Atypical primary melanoma of the umbilicus: A case report

“…Melanoma inci-dence rate is increasing and lifetime risk of getting melanoma is about 2.5% (1 in 40) for whites. This tumor can appear anywhere in the body 1 and sometimes in an atypical form 2,3 .…”