title: Large-cell neuroendocrine carcinoma of the skin: ultrastructural and immunohistochemical findings.
abstract: Large-cell neuroendocrine carcinoma (LCNEC) is an uncommon and aggressive neuroendocrine tumor, found mainly in the lung. Although LCNEC has been reported in various organs, LCNEC of the skin is extremely rare, poorly recognized and probably underestimated. Here we report a case of LCNEC of the skin, focusing on the histopathological and ultrastructural findings in detail. The patient was an 85-year-old Japanese woman presented with a mass on her right upper eyelid. Biopsy specimen showed an infiltrative mass with extension into the subcutis. Tumor cells were arranged in organoid and trabecular patterns with sheets, nests and trabecular cords. Extensive necrotic areas were observed. Most of the tumor cells were characterized by large cell size, polygonal shape, low nuclear-cytoplasmic ratio, coarse nuclear chromatin and frequent nucleoli. They were positive for CD56, NSE, AE1/AE3, CK7, and negative for CK20, TTF-1, synaptophysin and chromogranin A. A systematic radiographic examination revealed no additional neoplastic lesions other than the right upper eyelid mass. These findings suggest that the present case is a LCNEC of the skin. The existence of LCNEC in the skin should be recognized, as it is a rare variant of carcinoma that can potentially be misconstrued as a metastasis or as Merkel cell carcinoma.
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan. kotaro@nagase-skin.com.
authors: Kotaro
authors: K
authors: Nagase
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors: Hiromi
authors: H
authors: Kimura
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors: Naomi
authors: N
authors: Yonekura
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors: Shinichi
authors: S
authors: Koba
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors: Takuya
authors: T
authors: Inoue
authors: Division of Dermatology, Department of Internal Medicine, Faculty of Medicine, Saga University, Saga, Japan.
authors: Yutaka
authors: Y
authors: Narisawa
mesh_terms: D000369:Aged, 80 and over; D018287:Carcinoma, Large Cell / Q000175:diagnosis*; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis*; D005260:Female; D006801:Humans; D012878:Skin Neoplasms / Q000175:diagnosis*
keywords: dermatopathology; electron microscopy; neuroendocrine carcinoma; radiation therapy; skin cancer