Synchronous triple cancers of synchronous endometrial and ovarian carcinoma complicated by renal cancer: a case report.

Synchronous primary carcinoma of the endometrium and ovary is rare in clinical practice. Distinguishing between synchronous primary carcinomas and metastatic carcinomas is very important for the selection of subsequent treatment regimens. In addition, triple primary malignancies are even rarer. Here, we report a case of synchronous triple primary malignancies, including primary carcinomas of the endometrium, ovary, and kidney. We report a 60-year-old female patient who was diagnosed as synchronous primary carcinoma of the endometrium and ovary. Comprehensive staging surgery were performed. The molecular subtyping of endometrial cancer was mismatch repair deficiency. The whole-abdomen MRI was performed before the radiotherapy and a mass was found in the right renal parenchyma. The pathology showed papillary renal cell carcinoma. The result of germline genetic testing was negative (also negative for MLH1、MSH2、MSH6、PMS2、EPCAM). No recurrence or metastasis was observed during a 12-month follow-up period. This case report adds to the limited literature on synchronous triple primary malignancies. For synchronous endometrial and ovarian cancer, distinguishing between primary tumors and metastases is clinically critical. Notably, the presence of MMRd subtype in such synchronous tumors does not inherently indicate Lynch syndrome. This case underscores the importance of integrating molecular testing and clinical manifestations to accurately diagnose multiple primary malignancies and formulate tailored treatment plans.