Retroperitoneal Castleman's disease mimicking soft tissue tumour

Castleman's disease is a type of non-neoplastic lymphoproliferative disease having lymph nodal hyperplasia. It has two distinct microscopic types: hyaline-vascular type and plasma cell type. Clinically, it may present either as a solitary mass, most commonly in the mediastinum, or as a multicentric form whose features are generalized lymph-adenopathy, splenomegaly and involvement of other organs like the lungs and kidneys. Here we report a case of isolated retroperitoneal Castleman's disease, which presented as a lump in the iliac fossa in a young female. A clinico-radio-logical diagnosis of retroperitoneal soft tissue tumour was made and the patient underwent complete surgical excision. The exact diagnosis was only obtained at histopathology and there is no evidence of recurrence at six months follow-up.