Jejunal Malignant Peripheral Nerve Sheath Tumor with Preoperative Suspicion of Gastrointestinal Stromal Tumor: Report of a Korean Case and Literature Review

Background: Malignant Peripheral Nerve Sheath Tumors (MPNSTs) are defined as malignant tumors arising from a peripheral nerve or displaying nerve sheath differentiation. We report the first Korean case of MPNST of the ileum. Case Presentation: A 33-year-old female without family history of neurofibromatosis type I complained of lower abdominal pain. An abdomen computed tomography and enhanced magnetic resonance imaging of the pelvis confirmed a 5.6 cm heterogenous lobulated lesion in the ileum. Laparoscopic exploration revealed severe adhesion of the main ileal mass to the sigmoid colon. Laparoscopic adhesiolysis and segmental resection with anastomosis of the ileum was performed. On gross examination, the resected specimen was 6.5 cm and the tumor was located 10 cm proximal and 15 cm distal from the resection margins. In microscopic examination, the nucleus of the tumor cells was oval to elongated shape, showing moderate pleomorphism. Immunohistochemical staining showed that the main tumor cells were positive for S100 and about 10% of the tumor cells were positive for Ki-67. During the 12-month follow-up period, she presented no symptoms and the abdomen CT scans showed no evidence of distant metastasis in the thorax or abdominal recurrence. Conclusion: We report a rare case of a young female with a MPNST of jejunum, suspected of having GIST before surgery and an extensive review of the literature for MPNST in intestinal tract.