title: Epidermotropic primary neuroendocrine (Merkel cell) carcinoma of the skin with Pautrier-like microabscesses. Report of three cases and review of the literature.
abstract: Three cases of primary cutaneous neuroendocrine carcinoma involving the face are reported. In the first patient the tumor developed in the scar of a previously excised basal cell carcinoma of the nose, recurred locally, and metastasized to a regional lymph node 2 1/2 years after initial treatment. In the second and third patients the tumors were located on the forehead and were removed with a wide excision. In the second patient the tumor metastasized to regional lymph nodes 1 month after treatment. Light microscopic examination in all patients showed an undifferentiated, small cell, dermal tumor with prominent epidermotropism, forming Pautrier-like microabscesses. Immunohistochemical staining for neuron-specific enolase was positive, and ultrastructural examination revealed numerous cytoplasmic neurosecretory granules and paranuclear aggregates of intermediate-sized filaments. The literature concerning epidermal involvement by primary neuroendocrine carcinoma of the skin is reviewed; the relation with basal cell carcinoma and treatment are discussed.
mesh_terms: D000038:Abscess / Q000473:pathology*; D000368:Aged; D002277:Carcinoma / Q000473:pathology*; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007382:Intermediate Filaments / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D012867:Skin / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology*