LAUSR

A 35-year-old otherwise healthy man presented with incidentally discovered large mesenteric mass. The mass was discovered during his regular health checkup with abdominal ultrasound and he was referred to us. While he was asymptomatic, the mass was palpable on physical exam, and it was not tender. Computed tomography (CT) revealed a 7-cm hyper-vascular mass in the small bowel mesentery without any other lymphadenopathy (Fig. 1). All blood tests were within normal limits including lactate dehydrogenase (LDH) and hormonal panels. Iodine-123 meta-iodobenzylguanidine (MIBG) scintigram showed no uptake in the tumor. After multiple imaging studies and blood tests, his diagnosis remained inconclusive. As the mass was solitary without any detectable metastatic lesion, laparotomy with complete resection of the mesenteric mass was planned. Upon exploratory laparotomy via midline incision, a large mass was located near the base of the small bowel mesentery (Fig. 2). The small tributary vessels around the tumor were carefully ligated/divided, and the tumor was successfully excised with the superior mesenteric vein and artery intact. Entire small bowel appeared well-perfused, and small bowel resection was not necessary. The histological examination confirmed his diagnosis as Castleman disease (CD), hyaline vascular type. CD is a very rare lymphoproliferative disorder with unclear etiology and also known as angiofollicular lymph node hyperplasia. 1 Since it was first described in 1956, 2 more than 1000 cases with CD has been reported in the literature. 3 While all patients with CD present with lymphadenopathy at either single site (unicentric disease (UCD)) or multiple sites