GIANT PELVIC SCHWANNOMA OPERATED VIA COMBINED POSTERIOR AND ANTERIOR APPROACH

Case Presentation A 47-year-old male presented in 2020 at the oncology orthopedic clinic with complaints of constipation for 3 years, rectal tenesmus, the need to use suppositories, sharp stools, and urinary retention with a weak stream, requiring occasional bladder catheterization. On physical examination, there was pain upon palpation of the lower lumbar spine and sacral region, with a positive bilateral straight leg raise sign. A computed tomography scan performed the previous year showed an expansive lesion (10.4x11.4x12.8 cm) pre-sacral in location, likely of blastomatous nature. The lesion displaced pelvic structures—the sigmoid colon and bladder (displaced to the antero-superior region). A biopsy guided by CT and MRI was performed, revealing a 14x10.5x9 cm sacral expansive lesion that pushed adjacent structures without invading the bladder or intestinal loops, with a relationship to the right neural foramen of S3-S4. The biopsy result was a benign mesenchymal neoplasm—schwannoma. Surgical intervention was carried out by a joint team from orthopedics and coloproctology. Initially, a transverse posterior incision and sacrectomy at the S3 level were performed with tumor dissection by the orthopedic team. Then, a laparotomy approach was undertaken by the coloproctology team to remove the tumor intact, with no damage to the bowel or other structures. The patient had a favorable recovery and was discharged after 8 days. On his final follow-up with coloproctology, he continued to experience constipation, requiring lavage treatments.

Discussion Schwannoma is a rare tumor originating from Schwann cells and is the most common benign tumor of the peripheral nerve sheath. It presents a variety of morphological forms and rarely manifests malignantly. Most schwannomas are idiopathic, but they can occur in association with genetic syndromes. It is more common in individuals between the ages of 20 and 60. Complete surgical excision is the treatment of choice, but difficulties are often encountered due to the location and proximity to important nerves and blood vessels.

Conclusion Schwannomas is most often presented as retro-rectal tumors, and the approach is typically via the posterior (sacral) route. More complex cases may require combined surgical approaches, as seen in this case.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025