A 42 years old presented with history of mild abdominal discomfort for 6months without any comorbidity and other constitutional symptoms. USG abdomen was done which revealed a mass lesion in right hypochondriac region (? retroperitoneal). FNAC was inconclusive. CECT abdomen was suggestive of a well-definedheterogenous mass lesion in retroperitoneal region, displacing the body and tail of pancreas anterosuperiorly. On CT angio, tumour was hypervascular with multiple feeding vessels and distinct from pancreas and other nearby structures. Differential diagnosis of Neuroendocrine tumor, retroperitoneal sarcoma and neurogenic tumor was kept in mind. His serum chromogranin A level and other routine investigations were normal. So patient was planned for surgery in view of young age and symptomatic. On exploration a large mass of size 8×8 cms was found at root of mesentery, displacing Superior mesenteric vessels to right side and pancreas anterosuperiorly. Tumor was ditinctly separate from pancreas, bowel loops and adrenal gland. Tumor was resected en block. Histopathology revealed castleman’s disease.  Post operatively the patient recovered well.