A Case of Solitary Fibrous Tumor in the Pelvis Completely Resected Using the Hugo RAS System.

Solitary fibrous tumors (SFT) are rare mesenchymal neoplasms, and surgical resection with a negative margin is considered to have a good prognosis. It is commonly located in the thoracic cavity but rarely develops in the pelvis. One of the features of the Hugo RAS system is the independent robotic arm carts that enable high flexibility of settings and safe operations with reduced interference, even in a narrow pelvis, which may be particularly useful in surgery for pelvic masses. A 34-year-old woman presented to our hospital with a pelvic mass detected by transvaginal ultrasound during a prenatal check-up. Colonoscopy, computed tomography, and magnetic resonance imaging suggested a gastrointestinal stromal tumor, smooth muscle tumor, schwannoma, and SFT. However, since a definitive diagnosis could not be obtained and continuity with the rectum could not be ruled out, intersphincteric resection (ISR) was performed for diagnostic and therapeutic purposes. The pathological results showed complete resection of the SFT with negative margins, and the patient had a good postoperative course. Herein, we report the first case of safe and complete resection of a massive pelvic SFT using the Hugo RAS system.