抄録
A gastrointestinal stromal tumor (GIST) is the most common type of mesenchymal tumor of the gastrointestinal tract. A GIST often presents with an extra-intestinal growth pattern or peritoneal dissemination. It requires a differential diagnosis that includes malignant gynecologic tumors; however, ovarian metastasis of a GIST is extremely rare. We are reporting a case of a GIST metastatic to the ovary, diagnosed with laparoscopic surgery, which required differentiating from a malignant ovarian tumor. The patient was a 59-year-old woman referred to our department for a detailed evaluation of a left ovarian mass. She had a history of an intestinal GIST at the age of 56, which was completely excised. Three years after the operation, a chest-abdominal computed tomography imaged a left ovarian mass and multiple nodules in the mesentery, greater omentum, and the right lung. Because a GIST seldom metastasizes to the ovary, a diagnostic laparoscopy to differentiate from primary malignant ovarian tumors was performed. A left salpingo-oophorectomy and a biopsy of a peritoneal tumor was performed; the histopathologic diagnosis was a GIST metastatic to the left ovary with peritoneal dissemination. Consequently, the patient underwent molecular targeted therapy. The possibility of a mesenchymal tumor of the gastrointestinal tract such as a GIST should be considered in the differential diagnosis of a pelvic mass. Less invasive laparoscopic surgery facilitates intraperitoneal excision of the tumor and a histological diagnosis. Laparoscopic surgery can be useful for making a definitive diagnosis and treating malignant tumors.