A rare case of giant retroperitoneal neurilemmoma

Abstract

Neurilemmoma, also known as schwannoma or neurinoma, is a tumor that originates from neural sheath Schwann cells. Giant neurilemmomas derived from the retroperitoneum have rarely been reported. We herein describe a woman with a giant retroperitoneal neurilemmoma that was initially incorrectly diagnosed as an inflammatory abdominal mass. The tumor extended from the patient's hypogastrium to her pelvic cavity and measured 20 × 15 × 10 cm. The tumor was excised via laparotomy and diagnosed as a retroperitoneal neurilemmoma through histological and immunohistochemical examination. Although rare, particularly in the giant form, neurilemmoma should be considered as an important differential diagnosis in patients with a retroperitoneal tumor or inflammatory abdominal mass. Complete excision should be considered for the potential cure of giant retroperitoneal neurilemmomas.

Keywords: Giant neurilemmoma; Schwann cells; histology; immunohistochemistry; laparotomy; retroperitoneal tumor; treatment.

Figure 1.

Abdominal computed tomography revealed a capsulated cystic mass (18 × 14.5 × 14 cm) that encompassed the hypogastric region and pelvis. (a) Median sagittal section. (b) Coronal section. The mass exhibited a close relationship to the bladder, ureter, and rectum. No obvious bony destruction, defect, or resorption was seen.

Figure 2.

Intravenous pyelography showed left hydronephrosis due to the compression of the bladder and left ureter by the giant retroperitoneal mass.

Figure 3.

Histopathology of retroperitoneal neurilemmoma. The mass consisted of a proliferation of fusiform cells that formed a palisade or turbinate pattern ((a) ×10, (c) ×20) and of myxoid and degenerated tissue with cells and gelatinous substance ((b) ×10, (d) ×20). (e, f) S-100-positive cells (×20).