Small cell carcinoma of the ovary hypercalcemic type (SCCOHT): report of three cases and literature review

Background: Small cell carcinoma of the ovary, hypercalcaemic type (SCCOHT), is a rare ovarian tumor with hypercalcaeinia mainly affecting young females, but its histogenesis remains largely unknown, which makes it a challenge for effective diagnosis and treatment. This report describes three cases of SCCOHT in young women aging between 23 and 31 years. Material and Methods: All three patients with SCCOHT were subjected to sex hormone and nonnal blood calcium test, B-ultrasound, and microscopic examination for diagnosis. Expression of low molecular weight Cytokeratin, Vimentin, INI1, WT1, and SMARCA4 were determined by immunohisto-chemistry. Morphological features of cancer cells were observed using electron microscopy, and gene mutation was analyzed by DNA sequencing. Results: All three SCCOHT patients were diagnosed by pathology examination, B-ultrasound, and increased blood calcium level, and underwent surgical resection followed by chemotherapy. Immunohistochemistry showed positive expression of WT-1, CK, INI1, Vimentin, EMA, CD10, and CD56 in tumor tissues of all three cases, but no expression of a-Inhibin, Bcl6, PLAP, Alk, SALL4, SMARCA4, OCT3/4, SF1, Calretinin, MPO, CD20, AFP, CD5, hCG-beta, BCL2, ER, and S100. No mutations in FOXL2 gene were detected in these three SCCOHT cases. Two patients died within one year after surgery, and one was lost to follow-up. Conclusion: Three cases of young female SCCOHT patients were reported in this report, featured with poor prognosis even after surgery and chemotherapy.