ABSTRACT

A 51-year old male patient with a three-month history of constant and dull left flank pain was investigated by ultrasonography, computed tomography (CT) scan and magnetic resonance imaging (MRI) of the abdomen, which disclosed a 8 x 7 x 6 cm retroperitoneal pararenal mass with heterogeneous imaging characteristics and bright enhancement following intravenous contrast injection. Based on the hypervascularity of the mass and the lack of specific signs in the imaging investigation, lymphoma, sarcoma or vascular tumour were considered as probable diagnoses and the patient underwent an exploratory laparotomy. The histologic examination of the surgically resected specimen disclosed “a hyaline type of Castleman’s disease”. Further evaluation of the patient with antibody testing for HIV 1 and 2, as well as viral load by PCR for Herpes Virus-8 (HHV-8) were negative. Bone marrow aspiration, biopsy and immunophenotypic study did not disclose any evidence of lymphoma. Molecular study of the bone marrow for immunoglobulin heavy chain rearrangement showed a polyclonal pattern; serum protein electrophoresis did not show any evidence of hypergammaglobulinaemia and serum immunofixation electrophoresis did not show any monoclonal protein. A diagnosis of localized – unicentric type of Castleman’s disease was made. Castleman’s Disease should be included in the differential diagnosis of any solitary, heterogeneous and hypervascular retroperitoneal mass. Discovery of Castleman’s disease at any area of the body should be followed by a thorough imaging and laboratory work-up in order to exclude the multicentric type of the disease and the co-existence of lymphoma.