Blue nevus of the endocervix. A study of five cases.

The pathologic and immunohistochemical features of 5 cases of blue nevus of the endocervix are presented: 4 of them were studied ultrastructurally. The lesions were incidentaly discovered at microscopic examination and showed pigmented dendritic cells in the cervical stroma. Immunocytochemical examination showed all cases to be positive for S-100 protein. Ultrastructurally they contained melanosomes, were surrounded by a basement membrane, and displayed occasional desmosome-like devices. Histogenesis is discussed, and support for a schwannian origin is presented.