: [95][96] Schwannoma or neurilemoma is a well-defined, usually benign, tumor arising from the Schwann cell in the nerve sheath. It can present in any location as a solitary mass; however, it is rarely found in the abdomen. 1 We report a case of a benign schwannoma arising from the greater omentum, which was identified preoperatively by ultrasonography during investigation for symptomatic cholelithiasis. Cholecystectomy and excision of the tumor were performed by the laparoscopic method at the same time.
Case ReportWhile under investigation for symptomatic cholelithiasis, a 32-year-old Saudi female was incidentally found to have a 4.7 cm solid and cystic mass in the right subhepatic region on an ultrasound scan. A plain abdominal X-ray and routine hematological and biochemical investigations were all normal. Barium enema demonstrated extrinsic pressure on the hepatic flexure of the colon. Contrast-enhanced CT scan confirmed the presence of a well-defined round, low density, heterogenous mass related to the anterior and mesenteric aspect of the hepatic flexure (Figure 1). This was confirmed by MR imaging (Figure 2).Laparoscopy was performed using a 10-mm umbilical port, a 10-mm epigastric port and two 5-mm ports; one in the right midclavicular line and another in the right anterior axillary line. The mass was found to be arising from the greater omentum and adherent to, but not infiltrating, the wall of the hepatic flexure of the colon. A routine laparoscopic cholecystectomy was performed first. The mass was then mobilized from the colon and the greater omentum with relative ease, using a combination of sharp dissection and electrocautery, and a large feeding vessel was clipped and divided. Once free, the tumor was placed in an endopouch introduced through the epigastric port. The epigastric port incision was extended to 4 cm and the tumor was delivered through it intact. The patient made an uneventful recovery and was discharged from hospital three days later.Histopathology showed the tumor to have alternating Antoni A and B areas with minimal mitotic activity (less than two per ten high power fields). There was no increase in cellularity or flexiform morphology. These features were all diagnostic of a benign schwannoma.