Tripartite differentiation (squamous, glandular, and melanocytic) of a primary cutaneous neuroendocrine carcinoma. An immunocytochemical and ultrastructural study.
We report a case of primary cutaneous neuroendocrine carcinoma (PCNEC) with squamous, glandular, and melanocytic differentiation and associated Bowen disease. The paranuclear globular positivity of low-molecular-weight cytokeratins agrees with the ultrastructural observations of paranuclear fibrous bodies in the small neuroendocrine cells, while the diffuse cytoplasmic positivity corresponds to the sparse intermediate filaments in large cells with squamous differentiation. "Transitional forms" are characterized by both diffuse and globular cytoplasmic positivity for cytokeratins and by the ultrastructural evidence of neuroendocrine and squamous features. Therefore the ultrastructural demonstration of intracytoplasmic tonofibrils and tonofilaments, intercellular glandular lumina, lined by well-formed microvilli, and immature premelanosomes in the neurosecretory cells supports the proposed tripartite differentiation of neuroendocrine cells of this case of PCNEC.
U.O. di Anatomia ed Istologia Patologica e Citodiagnostica, USSL 70 Ospedale Civile di Legnano, Milan, Italy.
G
G
Isimbaldi
M
M
Sironi
G
G
Taccagni
P
P
Declich
A
A
Dell'Antonio
C
C
Galli
D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000473:pathology; D002277:Carcinoma / Q000473:pathology* / Q000648:ultrastructure; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004428:Ear Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D004431:Ear, External / Q000473:pathology* / Q000648:ultrastructure; D004848:Epithelium / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008544:Melanocytes / Q000473:pathology; D008940:Mitotic Index; D009490:Neurosecretory Systems / Q000473:pathology; D010751:Phosphopyruvate Hydratase / Q000032:analysis; D012878:Skin Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D013545:Sweat Glands / Q000473:pathology; D016708:Synaptophysin / Q000032:analysis
D016708:Synaptophysin; D010751:Phosphopyruvate Hydratase