Exfoliative cytology of primary poorly differentiated (small-cell) neuroendocrine carcinoma of the uterine cervix in ThinPrep material: a case report.

Poorly differentiated neuroendocrine (small-cell) carcinoma of cervical origin is a rare neoplasm that frequently metastasizes. Although the cytologic features have been described for conventional cervical smears, we know of no reports of its appearance in ThinPrep (TP) material. Therefore, we present a TP case of primary, small-cell carcinoma arising in a 46-yr-old female, confirmed by histologic and immunohistochemical analysis. Similar to conventional smears, the neoplastic cells occurred either individually or in small clusters. The cells were relatively monomorphic, with stippled chromatin and minimal amounts of cytoplasm. Unlike conventional smears, nuclear molding was not prominent (although overlap was observed), and nuclear smearing was not identified. The features are compared to TP cases of squamous-cell carcinoma, small-cell type, and endometrioid adenocarcinoma, which are close mimics of small-cell carcinoma. We conclude that correct diagnosis of small-cell carcinoma in TP is difficult, requiring a high degree of suspicion and immunohistochemical confirmation.