Endometrioid Adenocarcinoma Arising From Adenomyosis in a Premenopausal Woman: A Case Report

Abstract

Endometrioid adenocarcinoma derived from adenomyosis is rare. A premenopausal woman, aged 36, was referred to us for evaluation of multiple solid tumors in the pelvis. MRI revealed multiple tumors in uterine myometrium and omentum. Their T2 and enhanced T1-weighted imaging led us to a diagnosis of uterine sarcoma. Hysterectomy with bilateral salpingo-oophorectomy, omentectomy, and pelvic lymphadenectomy was performed. Histopathology revealed grade 3 endometrioid adenocarcinoma with squamous differentiation. Cancer nests were observed adjacent to the adenomyotic foci. Postoperative classification was pT3aN1M1. Rejecting adjuvant therapy, the patient died 16 days later from rapid enlargement and rupture of the metastasized liver and respiratory failure. An autopsy revealed mass lesions in the pelvic cavity and compressed small intestines causing ileus. Bone metastasis, multiple lymph node metastases including para-aortic, and lung metastases were also revealed. Multiple liver metastases had caused biliary obstruction and hepatic failure. The tumor-induced hypercoagulable condition resulted in multiple thromboses, which in turn led to hemorrhaging in the lungs and eventual respiratory failure. Histological examination of the pelvic mass lesions revealed mainly poorly differentiated carcinoma. The tumor cells contained bizarre nuclei and exhibited high mitotic activity. This case was high-potential malignant tumor as the tumor rapidly grew and infiltrated multiple organs in a short period. It was a type II carcinoma with biologically aggressive behavior.