成熟奇形腫の診断で腹腔鏡下卵巣嚢腫切除術を行い卵巣成熟奇形腫に伴う上皮内癌と診断した１症例

抄録

Background: Mature teratoma (MT) is the most common ovarian tumor, accounting for 10-20% of ovarian tumors. It is reported that 1-2% transform to malignancy, most transforming to squamous cell carcinoma. Squamous cell carcinoma found together with noninvasive squamous cell carcinoma in situ (CIS) is rarely reported, but it is even rarer that we find CIS alone, and standard treatment is not established. In this case, MT of the left ovary was diagnosed and laparoscopic cystectomy performed. Histological examination revealed CIS alone arising from MT.

Case: A 31-year-old G0P0 with no medical history visited our hospital for infertility treatment. An ovarian tumor measuring over 10 cm was found. She was diagnosed with MT of the left ovary by MRI and other preoperative examinations. She underwent laparoscopic left ovarian tumor cystectomy. Operative findings showed no adhesion, no peritoneal metastasis and normal ascitic fluid. The final diagnosis of the ovary was MT containing skin, hair and fat tissues, without immature elements. CIS was found in the partial stratified squamous epithelium. With informed consent, a left salpingo-oophorectomy and omentectomy were performed as a staging surgery. The patient conceived four months after the first operation, and delivered one year and one month after the first operation and was disease-free at the time of delivery.

Conclusion: CIS alone in ovarian MT is rare. To date, only around 10 cases have been reported, all diagnosed by postoperative pathology. For this reason, even if preoperative diagnosis is benign, we need to perform operations considering possibility of malignancy.