Abstract
The current study presents a mesenteric mesenchymal tumor case, with unusual features in diagnostic imaging and histology. A 16-year-old male was admitted to the hospital with abdominal pain. Computed tomography (CT) revealed an abdominal mass, 2 cm in diameter. The results of contrast-enhanced CT, magnetic resonance imaging and (18)F-fluorodeoxyglucose positron emission tomography indicated no specific features suggestive of its histology. Two arteries branching from the superior mesenteric artery were observed feeding the hypervascular tumor. After endoscopic and other laboratory findings revealed no additional lesions, the lesion was diagnosed as a primary mesenteric tumor. As the possibility of malignancy and future bleeding from this tumor could not be ruled out, a resection of the tumor was performed. During the surgery, the tumor, which was well circumscribed and hypervascular, was located in the mesentery of the jejunum. The resected tumor did not exhibit typical histological characteristics, and was labeled as 'myxoid smooth muscle neoplasm of uncertain biologic potential'. At 2 years after surgery, the patient remained well without evidence of recurrence. As primary mesenteric tumors are rare, particularly in young patients, it is considered important that this type of unusual tumor be included in the differential diagnosis for mesenteric tumors.