Retroperitoneal Mass—Castleman Disease

A 41-year old lady presented with upper abdominal pain for 1 month. Radiological imaging showed large well-defined solid mass with intense arterial enhancement. She was found to have raised serum chromagranin levels—suggestive of neuroendocrine tumor (NET). Hence, surgical excision of the mass was done. The final histopathology report was unicentric Castleman disease. Postoperatively, patient had raised creatinine with oliguria. Renal biopsy showed antiglomerular basement membrane type of crescentic glomerulonephritis. Castleman disease is a rare entity, and it should be considered in the differential diagnosis of retroperitoneal mass. This case is also reported for its rare involvement of the kidney.