Schwannoma extending from the umbilical region to the mid-thigh, compressing the major vessels of the right leg: A case report and review of the literature

Schwannomas are benign, usually encapsulated, nerve sheath tumours derived from Schwann cells. They commonly arise from the cranial nerves as acoustic schwannomas and are extremely rare in the pelvis and retroperitoneal area (<0.5% of reported cases) unless they are combined with Von Recklinghausen disease (type 1 neurofibromatosis). We report the case of a 23-year-old woman with a mass extending from the umbilical region in the abdomen to the upper two-thirds of the thigh. As this tumour is so rare, and in order to ensure optimal treatment and survival for our patient, a computed tomography-guided biopsy was performed before en bloc tumour excision. Because of the possibility of malignancy, complete excision of the mass was performed, with pelvic blunt dissection. Histological examination showed a benign neoplasm, originating from the cells of peripheral nerve sheaths; the diagnosis was a schwannoma. Abdominal schwannomas are rare neoplasms that can be misdiagnosed. Laparoscopy is a safe and efficient option for approaching benign pelvic tumours and may offer the advantage of better visualisation of structures owing to the magnification in laparoscopic view, especially in narrow anatomical spaces. However, in our case laparoscopy was not considered owing to the size and anatomical location of the tumour.