title: Sebocyte-like cell primary cutaneous melanoma: a rare cytologic variant of malignant melanoma.
abstract: Although rising incidence rates of cutaneous melanoma have been observed during the last 4 decades in white populations worldwide, the sebocyte-like cell variant has been described only twice in the literature to date. In our case, a 64-year-old man presented for evaluation of a changing pigmented lesion on the left upper back. Excision of the lesion revealed an invasive melanoma with a Breslow depth of 3.3 mm. Microscopic sections showed a predominantly dermal-based tumor composed of sheets and nests of enlarged epithelioid melanocytes, most of which showed an uncommon phenotype with multivacuolated cytoplasms and scalloped nuclei, features that gave them a strong resemblance to mature sebocytes. The lesional cells expressed S100 protein, Melan-A, and p16, whereas adipophilin was positive only within the sebocyte-like component of the neoplasm and showed focal nonspecific staining. The patient's sentinel lymph node biopsy was positive for micrometastases, although a subsequent position emission tomography scan was unremarkable. Sebocyte-like melanocytes are a rare distinctive type of melanocytes that can be found mostly in benign but also in malignant melanocytic lesions. They usually present focally within the lesions and, therefore, do not represent a diagnostic problem in nevus or primary cutaneous melanoma. However, when sebocyte-like melanocytes are the main cellular component of a melanocytic lesion or when they are found in the context of metastatic melanoma, they may create a potential diagnostic pitfall; for this reason, awareness of this cell type is important.
authors.affiliation: *Department of Dermatology, Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain; †Department of Pathology, Hospital Universitario Santa María del Rosell, Murcia, Spain; and ‡Dermatophatologisches Gemeinschaftslabor, Friedrichshafen, Germany.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Molina-Ruiz
authors.forename: Sebastián
authors.initials: S
authors.lastname: Ortiz-Reina
authors.forename: Carmen
authors.initials: C
authors.lastname: Carranza
authors.forename: Heinz
authors.initials: H
authors.lastname: Kutzner
authors.forename: Luis
authors.initials: L
authors.lastname: Requena
mesh_terms: D006801:Humans; D008297:Male; D008544:Melanocytes / Q000473:pathology*; D008545:Melanoma / Q000473:pathology*; D008875:Middle Aged; D012878:Skin Neoplasms / Q000473:pathology*