Laparoscopic resection of a retroperitoneal pelvic schwannoma

Abstract

Schwannomas are rarely located in the pelvis. A 54-year-old woman was found incidentally to have a tumor in the abdomen. Abdominal computed tomography and magnetic resonance imaging revealed a well-defined, heterogeneous tumor, 5 cm in diameter, in the pelvic cavity. With a diagnosis of a mesenteric tumor, a laparoscopic procedure was performed. Intra-operatively, an elastic tumor was identified in the pelvis adjacent to the right internal iliac vein and ureter. The tumor was dissected free from adjacent structures using Liga-Sure and blunt maneuvers. A complete laparoscopic excision was performed. Histopathological examination revealed a benign schwannoma. The patient had an uneventful post-operative course, and was discharged on the fourth post-operative day. Laparoscopic treatment is useful and feasible for retroperitoneal pelvic schwannoma, with minimal invasiveness and an early post-operative recovery. Thus, this procedure may be the first-choice surgical procedure for retroperitoneal pelvic schwannomas.

Figure 1:

Ultrasonography of the pelvis shows a 5 × 4.3 cm solid and an iso-echoic mass.

Figure 2:

Contrast enhanced-CT shows a 5 × 4 cm solid, well-defined, heterogeneous mass in the right side of the pelvic cavity.

Figure 3:

MRI shows that the tumor is a homogeneous hypointensity on T1-weighted images (A) and a heterogeneous slight hyperintensity on T2-weighted images (B) in a right side of the pelvic cavity.

Figure 4:

Sagittal MRI sections show the mass to be intricately related to the anterior presacral fascia.

Figure 5:

Laparoscopic findings of schwannoma in the pelvis. 1, schwannoma 2, right ureter 3, rectum 4, right iliac vessel.

Figure 6:

The specimen is an elastic hard, 5 × 4 cm mass with an integral envelope. On sectioning, it is yellow and white in color, predominantly solid with cystic change.

Figure 7:

Histologic findings of schwannoma in the pelvis (hematoxylin and eosin, ×200). (A) The Antoni A pattern is composed of spindle cells arranged in intersection fascicles. Nuclear palisades are seen and mitoses are rarely observed. (B) The Antoni B pattern is composed of loose hypocellular tissue.