Malignant peripheral nerve sheath tumor of mesocolon: A rare case

Abstract

Malignant peripheral nerve sheath tumor (MPNST) is a soft-tissue sarcoma arising from or differentiating toward peripheral nerve sheath cells. It accounts for 5%–10% of soft-tissue sarcomas. The most common sites of origin are proximal portion of upper, lower limbs and trunk. MPNST arising from the nerve plexus of gastrointestinal tract is extremely rare, and only very few cases have been reported in literature. In this report, we are describing a case of MPNST from mesocolon. An 82-year-old male presented to hospital with complaint of pain abdomen and feeling of lump on the left side of lower abdomen for the past 2 months. On contrast-enhanced computed tomography (CECT) of chest and abdomen, there was 15 cm × 10 cm mass palpable in left lumbar region without ascites and multiple random subpleural nodules in bilateral lung. Intraoperatively, there was 15 cm × 10 cm hard irregular mass in left paracolic gutter infiltrating mesentry of descending colon. Left hemicolectomy was performed with end-to-end anastomosis. Histopathological examination revealed malignant peripheral nerve sheath tumor, and on immunohistochemistry, tumor cells were positive for S-100 and negative for C-kit and Smooth Muscle Actin (SMA). The patient was started on tamoxifen in view of old age and lung metastasis. The patient is on follow-up from 2 years with stable disease. In this report, we highlight the possibility of clinical differential diagnosis of MPNST arising from mesocolon should be kept while dealing with mesenchymal tumors of colon. Radical surgery with negative margins is required for achieving palliation, and adjuvant tamoxifen could offer advantage in patient who cannot tolerate chemotherapy.

Keywords

• chemotherapy
• colon
• malignant peripheral nerve sheath tumor