レチウス腔に発生したAggressive angiomyxomaに対して内視鏡手術を行った１例

抄録

　Aggressive angiomyxoma (AAM) is a benign mesenchymal neoplasm arising in the pelvis, perineum, and vaginal wall of premenopausal women. Its recurrence rate reaches approximately 50%, and it is treated with combined surgical resection and gonadotropin-releasing hormone (GnRH) agonists. Laparoscopic surgery is superior to laparotomy in terms of accessibility and a detailed and magnified view of the surgical field. Learning the anatomy of the less familiar Retzius space may be useful for gynecologists.

　A 46-year-old G2P2 presented with an incidental finding of a pelvic mass on computed tomography. Magnetic resonance imaging revealed a 3.5-cm spindle-shaped mass between the left pubic bone and the bladder with clear demarcations from the vagina and bladder. Preoperative diagnosis suggested AAM located in the Retzius space. Because resection using a single approach from the perineal region was considered difficult, we performed laparoscopic resection with visualization of the Retzius space from the abdominal cavity, which revealed a pedunculated mass arising from the left internal obturator muscle. Because of unclear borders, we dissected the mass while observing the inside of the bladder with a cystoscope. The mass was resected, placed in a retrieval bag, and retrieved from the umbilicus. The final pathological diagnosis was AAM and prophylactic GnRH agonists were administered. No regrowth occurred in 2 years and 4 months postoperatively.

　The Retzius space between the pubic bone and bladder, also known as the retropubic space or prevesical space, is often visualized during urological surgeries. During laparotomy, the pubic bone blocks the Retzius space. Contrastingly, laparoscopy allows less invasive and safer resection of AAM arising from the left internal obturator muscle. Laparoscopic surgery for benign tumors in the Retzius space may be a feasible option as minimally invasive procedure.