Combined desmoplastic melanoma of the vulva with poor clinical outcome

Desmoplastic melanomas in an unusual variant of melanoma that usually occurs in sun-damaged skin of elderly people. Desmoplasia may be the prominent features of the lesion or represent a portion of an otherwise non-desmoplastic melanoma; these latter are called "combined" desmoplastic melanoma. Desmoplastic melanomas of the vulva are rare. Herein, we report a case of "combined" DM of the labia minor consisting of a superficial spitzoid component and a deeper spindle desmoplastic component. Protein S-100 expression was ubiquitous, while MART-1 and HMB-45 were limited to the superficial spitzoid component and were negative in desmoplastic areas. Notably, the nodal metastasis retained the same biphasic pattern seen in the primary tumour. The patient died of widespread metastatic disease 3 years after diagnosis.