[Giant sacral schwannoma with pelvic extension. Therapeutic strategy. Apropos of a case].

A 48-year-old woman was admitted for acute urinary retention. Clinical pelvic examination disclosed a voluminous retro-rectal mass. Plain X-rays, pelvic echography, computerized tomography and MRI were all consistent demonstrating the presence of a 15cm-diameter lesion in the pelvic space with sacral erosion at S3-S4 and extension in the sacral canal up to S2. After a preoperative embolization, the tumor was removed in a two-stage procedure. First, an anterior transabdominal approach dissected the superior and lateral aspects of the tumor. To make easier the intra-abdominal dissection and to avoid any rectosigmoid necrosis, hysterectomy and rectosigmoid section with an end-colostomy were performed. Lastly, a piecemeal removal of the whole tumor was achieved using a posterior approach. At 6 months postoperatively, she recovered a satisfactory urinary control and the colo-rectal anastomosis was then successfully performed. Clinically only a slight hypesthesia of the left perineum was present. In the recent literature, 21 cases were described with similar clinical presentation and similar technical problems to achieve a complete treatment. In the discussion, details of the surgical anterior and posterior approaches are given. Before deciding the most appropriate surgical approach for such a mass, a biopsy is useful to determine whether total removal is relevant. A preoperative embolization can help to reduce the duration of the procedure and the loss of blood.