A rare case of combined endometrioid adenocarcinoma arising from uterine adenomyosis and clear cell carcinoma arising from parametrical deep endometriosis

Abstract

Abstract Background Carcinomatous changes from the ectopic endometrial glands in endometriosis have been reported in many studies, but malignant transformation from uterine adenomyosis/adenomyoma is rare. And clear cell-like adenocarcinoma represents a seldom-encountered malignant pathological variant of ectopic endometrium. Case presentation This case report presents a case of a 44-year-old nulliparous woman begun with abdominal pain and intestinal obstruction. Past medical history showed laparoscopic ovarian endometriotic cyst excision. Ultrasound indicated adenomyoma and a parametrical hypoechoic nodule with abundant blood flow signals and unclear boundaries. Deep invasive endometriosis was considered preoperatively. The patient underwent laparoscopic subextensive hysterectomy and bilateral adnexa resection. Chocolate cyst-like lesion was observed in the parametral lesion. Postoperative pathological examinations suggested endometrioid adenocarcinoma arising from eutropic endometrium and adenomyoma. Left parametrical lesions suggested poorly differentiated endometrioid adenocarcinoma combined with clear cell carcinoma. CD10 + endometrial stromal cells were observed surrounding tumor cell masses. The patient underwent subsequent transabdominal tumor cell reduction surgery and chemotherapy. Combined with surgical founding and pathological characters of the left parametrical adenocarcinoma, the parametrial lesions were more likely to be carcinomatous changes of the original deep endometriosis. Conclusion We herein present a rare case of combined endometrioid adenocarcinoma arising from uterine adenomyosis and clear cell carcinoma arising from parametrical deep endometriosis that may help inspire additional studies in the future.