Merkel cell carcinoma of the skin: the structure and origin of normal Merkel cells.

摘要: A series of 15 Merkel cell tumours skin is reported. They occur dominantly on the head and neck extremities elderly women, frequently presenting as a reddish nodule. Three cases were associated with squamous carcinoma at same site, an association deserving further study. There are two main patterns: commoner one takes form trabecular in dermis mimicking metastatic carcinoma, including oat-cell neuroblastoma: dissociated-cell mimicks malignant lymphymphoma. The triad vesicular nuclei very small nucleoli, abundant mitotic activity apoptosis so characteristic to be virtually pathognomonic conjunction structural features. Argyrophilia common, but Bourn fixation necessary demonstrate it regularly. Small round secretory granules (89 ± 18 nm) narrow haloes, abundance intermediate size filaments among ultrastructural hallmarks. close similarity between better differentiated tumour cells normal cells. neural crest origin MC doubt both basis studies development regeneration from study tumours.