Desmoplastic melanoma presenting as primary alopecia neoplastica: a report of two cases.
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.
Department of Pathology, Cleveland Clinic, Cleveland, OH, USA.
Emily M
EM
Erstine
Department of Pathology, University of New Mexico School of Medicine, Albuquerque, NM, USA.
Hillary R
HR
Elwood
Department of Surgery, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Kent C
KC
Westbrook
Departments of Pathology and Dermatology, University of California, San Francisco, CA, USA.
Timothy H
http://orcid.org/0000-0002-8102-3348
TH
McCalmont
Departments of Pathology and Dermatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
Sara C
SC
Shalin
Departments of Pathology and Dermatology, University of Arkansas for Medical Sciences, Little Rock, AR, USA. jmgardnermd@gmail.com.
Jerad M
http://orcid.org/0000-0001-7397-2159
JM
Gardner
D000368:Aged; D000505:Alopecia / Q000378:metabolism / Q000473:pathology; D001706:Biopsy; D005260:Female; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology; D006801:Humans; D008545:Melanoma / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D009418:S100 Proteins / Q000378:metabolism*; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology
D009363:Neoplasm Proteins; D009418:S100 Proteins
alopecia; alopecia neoplastica; desmoplastic melanoma