Cytological features of small cell neuroendocrine carcinoma of the uterine cervix

Small cell neuroendocrine carcinoma (SCNEC) of the cervix is rare. Cytological examination is a valuable tool for detecting cervical lesions; however, due to the rarity of cervical SCNEC, its accurate diagnosis remains challenging. In some cases, cervical SCNEC coexists with other non-neuroendocrine components, forming what is known as combined SCNEC. The cytological features of combined SCNEC have not been well-documented. The present study retrospectively analysed the clinicocytological features of cervical SCNEC, including combined SCNEC. A total of six patients diagnosed with cervical SCNEC (three with pure SCNEC, two with combined SCNEC and one with carcinosarcoma) who underwent preoperative cervical cytological examination and were diagnosed with SCNEC through biopsy and/or surgical resection were included in the current study. The median patient age was 55 years, and the combined SCNEC cases included both SCNEC and adenocarcinoma components. Retrospective cytological examination revealed that cervical specimens from all six patients contained SCNEC components, characterised by clusters of small round neoplastic cells with round to oval nuclei, fine chromatin, and inconspicuous nucleoli in a necrotic or inflammatory background. Among the two patients with combined SCNEC, one exhibited an adenocarcinoma component, whereas the patient with carcinosarcoma had a sarcomatous component. These findings suggested that most cases of SCNEC can be detected in cervical cytological specimens. Additionally, other combined carcinoma components may be identified. Notably, careful cytological examination may facilitate the accurate diagnosis of cervical SCNEC, enabling timely treatment for this aggressive malignancy.