Pathological examination of a placenta leading to the diagnosis of endometrial carcinoma: A case report

Although endometrial cancer is extremely rare during pregnancy, the placental metastasis of endometrial cancer is even rarer. The current study presents a case of endometrial carcinoma that was diagnosed through the pathological examination of the placenta. A 35-year-old primipara woman who underwent frozen-thawed embryo transfer at the Keiai Ladies Clinic in Tokushima prefecture (Japan) received regular prenatal check-ups. She was transferred to Tokushima University Hospital for perinatal management due to the preterm premature rupture of membranes at 21 weeks and 6 days gestation. The administration of antibiotics and tocolytic agents was continued; however, labor pain occurred at 23 weeks and 3 days gestation, and a female fetus weighing 524 g was delivered vaginally. The placenta weighed 262 g and had no macroscopic abnormalities. It was submitted for pathological examination, which revealed metastatic adenocarcinoma (clear cell carcinoma suspected). The patient was subsequently diagnosed with endometrial cancer (stage I suspected), and underwent abdominal total hysterectomy, bilateral salpingo-oophorectomy, partial omentectomy and pelvic lymph node dissection. The final diagnosis was stage IA endometrial cancer (endometrioid carcinoma, G2). At 1 year after surgery, there was no evidence of disease. The present case highlights the importance of considering the emergence of endometrial cancer during pregnancy.