Rare case of Castleman disease involving the pancreas.

Castleman disease, also known as angiofollicular lymph node hyperplasia, is an uncommon tumor involving lymph node tissues. The most common location is in the thorax presenting as a mediastinal mass. In the abdomen, most of the lesions are located in the pelvis, mesentery, and retroperitoneum. Only nine other cases of Castleman disease involving the pancreas have been described. We report a case of Castleman disease (hyaline vascular type) presenting as a pancreatic mass and an enlarged spleen. A 23-year-old woman presented with a 2-month history of abdominal pain localized to the left upper quadrant. Ultrasound and CT demonstrated a large retrogastric pancreatic mass and an enlarged spleen. Distal pancreatectomy and splenectomy were performed. Histopathologic examination revealed a markedly enlarged lymph node showing germinal centers with hyalinization and prominent follicular dendritic cells meshwork surrounded by concentric layers of small lymphocytes. Within the interfollicular area were regions of increased vascularity. BCL2, CD20, and CD79a show expanded mantle zones with a concentric targetoid arrangement of small lymphocytes. This is a case of unicentric Castleman disease of the hyaline-vascular type, which presented with signs and symptoms of a primary pancreatic neoplasm.