placental site trophoblastic tumor（PSTT）に対して腹腔鏡下手術で診断を得た一例

抄録

　Placental site trophoblastic tumor (PSTT) is a rare trophoblastic disease in which intermediate trophoblastic cells form a mass in the lumen and myometrium of the uterus. PSTT is characterized by relatively low hCG levels and chemotherapy resistance. Symptoms include amenorrhea and irregular genital bleeding, but there are few other clinical symptoms. In this study, we report a case of PSTT diagnosed by laparoscopic surgery for a uterine tumor.

　The patient was 28 years old, G2P1. Her chief complaint was amenorrhea at adminstration. The blood level of β-hCG was 18.5 mIU/ml with no evidence of normal pregnancy. In MRI, a 32 mm mass at the uterine fundus was suspected to be a red degenerative myoma. hCG levels gradually increased and methotrexate was administered, but hCG levels did not decrease. A pelvic MRI was performed again, and the mass in the uterine fundus had shrunk and was protruding into the angle of the left uterine horn. Therefore a laparoscopic surgery was performed for diagnostic purposes. The tumor that was thought to be a myoma was removed by wedge resection of the angle of the left uterine horn because it was found to have invaded the surrounding muscle layer on gross examination. Postoperative histopathological examination revealed the diagnosis of PSTT, so a TLH was performed. No obvious residual lesions were found in the removed uterus. The postoperative hCG level was confirmed to be negative. We will continue to monitor the patient closely.