Case Presentation: A 53-year-old woman was admitted with the complaints of abdominal pain, abdominal distension and postmenopausal bleeding. Her transvaginal ultrasound scan revealed a cystic mass containing papillary projections with the dimensions of 6.5 × 5 × 4 cm on the right ovary. Level of (carbohydrate antigen) (CA) 125 was 223 IU. Dilation and curettage revealed endometrioid adenocarcinoma. Debulking surgerywas carried out. Histopathological diagnosis was grade 2 adenocarcinoma with squamous differentiation for endometrial cancer and grade 2 endometrioid adenocarcinoma with squamous and mucinous differentiation for ovarian cancer. The stage was 1A for endometrial cancer and 1A for ovarian cancer. 12 months after the operation CA 125 level was 112 IU. Positron emission tomography (PET) scan showed a small lesion (1.5×1.5 cm) in the pelvic cavity with increased fluorodeoxyglucose (FDG) uptake. Five months after the chemotherapy, CA 125 level elevated from 10 to 60 IU and subsequent magnetic resonance imaging (MRI) revealed a tumoral mass with the dimensions of 3×2.2 cm. A second laparotomy was performed and the metastasis was excited. The tumor was endometrioid adenocarcinoma with infiltration in the serosa and muscularis propria of sigmoid colon.

Conclusion: It is necessary to consider the presence of double cancer in the diagnosis and treatment of gynecological cancers.