Malignant Transformation from Endometriosis to Atypical Endometriosis and Finally to Endometrioid Adenocarcinoma within 10 Years
A 33-year-old woman (gravida 0, para 0) was referred to Osaka Central Hospital (Osaka, Japan) for gynecological, fertility-preserving laparoscopic surgery. According to her surgical history, two prior laparoscopic surgeries had been performed to treat endometriosis. At the age of 24, she underwent her first laparoscopic cystectomy for left ovarian endometrioma at a community hospital. When she was 29 years old, a second laparoscopic surgery (laparoscopic cystectomy for a right ovarian cyst) was performed at the same institution. The histological examinations of both specimens revealed benign endometriotic cysts. However, approximately 7 months following the second surgery, ultrasonographic and pelvic examinations revealed bilateral ovarian cysts. In response, we administered gonadotropin-releasing hormone agonist therapy (buserelin acetate, 900 μg/day) every 6 months. Upon termination of treatment, the cysts gradually enlarged. At 33 years of age, our patient got married. She desired children and was therefore referred to our institution for fertility treatment via laparoscopic surgery.\nUpon presentation to our hospital, both her ovaries were enlarged (left, 3 cm; right, 4 cm) because of endometrioma. MRI and ultrasound scans showed no solid component within the bilateral cysts. Initially, we considered terminating the hormonal therapy to allow for natural pregnancy. However, she did not become pregnant during a follow-up period of approximately 5 months. Therefore, our patient consented to a third laparoscopic procedure to improve her fertility.\nA preoperative MRI scan revealed a solid 2-cm component of her right ovarian endometrioma. Although the imaging was not enhanced, the possibility of malignancy could not be overlooked. Therefore, we recommended exploratory laparotomy to be performed at another institution. However, the patient and her husband rejected this recommendation and strongly insisted upon a third laparoscopic surgery at our institution. Our patient was fully informed of the treatment options and submitted written consent after which we agreed to perform the third laparoscopic surgery.\nNotably, the third laparoscopic surgery was performed at our institution approximately 10 years after the first surgery. The patient's cancer antigen 125 serum level was within the normal range and both ovaries, which were strongly adhered to surrounding tissues, were enlarged (right, 5 cm; left, 4 cm). The cul-de-sac was obliterated with dense pelvic adhesions. Laparoscopic cystectomy for both ovarian cysts and adhesiolysis were performed.\nThe patient had an uneventful recovery. A histological examination revealed a transition between the endometrioid adenocarcinoma and the directly adjacent endometriosis (fig. ). The cytological result of the small amount of ascites was negative. We reviewed the external slides of the previous two surgeries and confirmed the diagnosis of atypical endometriosis based on the second specimen (fig. ). The patient was diagnosed as having FIGO stage 1c(2), grade 1 ovarian endometrioid adenocarcinoma. Once informed of our diagnosis, our patient desired to attempt to preserve her fertility and rejected complete curative surgery for ovarian cancer.\nFor the fourth surgery, we performed laparoscopic salpingo-oophorectomy of the right ovary, biopsy of the left ovary and partial omentectomy. All specimens showed no pathological malignancy. Postoperatively, the patient underwent three courses of chemotherapy consisting of 175 mg/m2 of paclitaxel and carboplatin (AUC 5) every 3 weeks. A follow-up examination conducted 7 years after the fourth surgery showed no evidence of recurrence.