Small cell carcinoma of the gynecologic tract: a multifaceted spectrum of lesions

Objective: Small cell carcinoma (SmCC) of the female genital tract constitutes a diagnostic and clinical challenge given its rarity and the lack of standardized therapeutic approaches. Here we review the morphological, clinical and molecular features of gynecologic SmCCs and discuss potential areas for future research.

Methods: Data for this review article were identified by searches of PubMed, EMBASE and the Internet using the search terms "small cell carcinoma" or "neuroendocrine carcinoma" and "gynecologic", "uterine cervix", "cervix", "uterus", "endometrium", "ovary", "vagina", "fallopian tube" or "vulva", and research articles published in English between 1972 and February 2014 were included.

Results: SmCCs arising from different organs within the gynecologic tract share the same histopathologic characteristics, which closely resemble those of small cell lung carcinoma. The expression of at least one immunohistochemical neuroendocrine marker is a common finding. The uterine cervix is the most frequent site of SmCC in the female genital tract. HPV infection seems to play a role in the development of cervical SmCC but not in cancers of other gynecologic sites. FIGO stage is an established prognostic factor, in particular in SCCs of the cervix. Irrespective of the site, SmCCs of the gynecologic tract display an aggressive clinical behavior with few reported long-term survivors. The therapeutic management includes surgery, radiotherapy and chemotherapy.

Conclusions: Despite the potential differences in etiology and risk factors, SmCCs from different sites of the gynecologic tract have similar morphologic appearances and clinical behavior. Recent genomic analyses of small cell carcinoma of the lung have revealed potential driver genomic alterations. We posit that the comprehensive genomic characterization of gynecologic SmCCs may lead to the identification of markers that result in an improvement of diagnostic reproducibility of SmCCs of the gynecologic tract, and of molecular aberrations that may be exploited therapeutically in subgroups of the disease.