A 46-Year-Old Woman with Primary Infertility and a Diagnosis of Microcystic Stromal Tumor of the Ovary Confirmed by Histology and Gene Sequencing: A Case Report and Review of the Literature

BACKGROUND Microcystic stromal tumor (MCST) of the ovary is a rare entity with distinct pathological and molecular features. However, a lack of awareness of ovarian MCST can lead to delayed diagnosis or misdiagnosis. We present a case of ovarian MCST and review all previously reported cases and discuss their clinical and pathological characteristics. CASE REPORT A 46-year-old woman with primary infertility due to polycystic ovary syndrome presented with bleeding and pain. Radiological images showed a complex solid and cystic adnexal mass. Microscopically, the tumor was lobulated with cellular regions separated by fibrous plaques and small anastomosing cysts, consistent with an ovarian MCST. The tumor cells showed positive staining for vimentin, CAM 5.2, CD10, s-Catenin, CD99, and cyclin D1. Genetic sequencing showed a point mutation in the CTNNB1 gene, with no mutations in the APC, BRCA1, and BRCA2 genes. The patient underwent surgery and was disease-free at 24 months after her initial diagnosis. CONCLUSIONS The diagnosis of ovarian MCST should consider the differential diagnosis of cystic tumors of the ovary. Further research is encouraged to elucidate the various molecular pathways involved in the pathogenesis of this tumor and to determine its optimal treatment and long-term prognosis.