RESUMEN
@#Synchronous malignant tumors are two primary tumors diagnosed at the same time during surgery. A postmenopausal, nulligravid, presented with vaginal bleeding. Ultrasound revealed an endometrial and right ovarian mass, both with nonbenign features. Cancer Antigen 125 and Human Epididymis Protein 4 were elevated. She underwent extrafascial hysterectomy with bilateral salpingo-oophorectomy with the frozen section of the endometrium and right ovary, followed by complete surgical staging. Histopathology report was endometrioid endometrial carcinoma and high-grade serous ovarian carcinoma. The endometrial and ovarian tissues tested positive for vimentin and Wilm's Tumor 1 (WT1), respectively, suggesting both are primary independent tumors. The pelvic lymph nodes and recto-sigmoid lymph nodes tested positive for vimentin and negative for WT1, suggesting endometrial tumor metastasis. The final diagnosis is synchronous endometrioid endometrial carcinoma Stage IIIC1 and high-grade serous ovarian carcinoma Stage IA, right ovary.