[Clinical and pathological characteristics of ovary mature cystic teratoma squamous cell carcinoma and primary ovarian squamous cell carcinoma].

To explore the clinical and pathological characteristics of squamous cell carcinoma arising in ovary mature cystic teratoma (MCT) and primary ovarian squamous cell carcinoma (POSCC). Retrospective analysis was conducted on the clinical and pathological characteristics, immunophenotype and prognosis of five cases of ovarian squamous cell carcinoma (OSCC). Next generation sequencing (NGS) test was performed on one case of POSCC to analyze its molecular genetic characteristics. The age of five patients (including four MCTs and one POSCC) ranged from 43 to 68 years. There were one case of simultaneous involvement of both ovaries, one case of left ovary, and three cases of right ovary. Microscopically, four cases of tumors were composed of MCT and squamous cell carcinoma. Among which, one case only showed squamous cell carcinoma components and no accompanying lesions were found in the surrounding area. Immunohistochemistry staining showed that all cases were positive for p40, CK5/6, p63; P53 was positively expressed in two cases; and the proliferation index Ki-67 ranged from 30% to 50%. One POSCC NGS test harbored 12 somatic mutations, among which 3 mutations with clear or potential clinical significance were BRCA1 gene (p.G263fs), TP53 gene (p.R273C), and ERBB2 gene (copy number amplification). Four patients underwent ovarian cancer debulking surgery; one patient underwent radical resection of ovarian cancer and platinum-based chemotherapy was given after surgery. During 3-10 months of follow-up, 3 patients died; 1 patient was alive; and 1 patient was lost to follow-up. OSCC is a kind of ovarian cancer with low incidence rate. Most of these tumors arise from malignant transformation of MCT. POSCC is extremely rare. The treatment mainly involves surgical resection, supplemented by platinum-based combination chemotherapy after surgery. OSCC progresses rapidly, and has a poor prognosis.