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Hepatobiliary and Pancreatic: Castleman disease of the pancreas diagnosed by endoscopic ultrasound

A 52-year-old female patient was admitted to our hospital with mild intermittent, upper abdominal pain that aggravated after meals for 10 days. She has a 1-year medical history of chronic gastritis. She has no past surgeries or other medical diseases. Her laboratory test results including a complete blood count, liver, and renal function tests, carbohydrate antigen 19-9, alpha-fetoprotein, and carcinoembryonic antigen levels were normal. A physical examination also failed to reveal any abnormality. Her initial abdominal contrast-enhanced computed tomography scan revealed a lesion in the pancreas suggestive of a pancreatic neuroendocrine tumour. On contrast-enhanced magnetic resonance imaging (MRI) demonstrated a 4.5 × 3.2-cm well-defined soft tissue mass arising from near the pancreatic body (red arrow), without pancreatic duct dilation. The lesion enhanced strongly on arterial phase (Fig 1a), and became weaker and more heterogeneous during the portal venous phase. Endoscopic ultrasound (EUS) revealed a hypoechoic and hypervascular pancreatic mass (Fig. 1b). Moreover, Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed (Fig 1c), and cytologic examination revealed polymorphous lymphocytes and a partially intact lymphoid follicle with a piercing fine capillary vessel. There were expanded follicles replaced by a dense infiltration of small, mature, lymphocytes devoid of follicular center cells (Fig. 1d) (200×). Based on these findings, the differential diagnoses of pancreatic neuroendocrine tumour, ectopic phaeochromocytoma and Castleman disease (CD) were made. The patient underwent a laparotomy. Intraoperatively, a mass with adequate blood supply was found closely adhered to the upper pancreatic edge. The tumor size was about 4.8 × 3.5 × 3.2 cm. It was well demarcated and had a soft flexible texture (Fig. 2a). The whole tumor was resected along the pancreas and surrounding tissue gap, and the pancreatic tissue was preserved. Histology revealed that the lesion was an enlarged lymph node, with follicular hyperplasia, marked vascular proliferation, and regressed germinal centers (Fig. 2b). Immunohistochemical studies provided more messages than the preoperative results and proved T-lymphocytes that is negative for bcl2 in follicular germinal center cells and positive for CD20, CD21, CD43, CD79a, and CD3 in the interfollicular area (Fig. 2c–h). So the final definite diagnosis was CD (type of hyaline-vascular). The postoperative course was uneventful, and the patient recovered well without any postoperative radiotherapy or chemotherapy. After 12 months of follow-up, there were no complaints or recurrence related to the disease.