extranodal castleman disease of lower extremities: a case report of a rare presentation

Castleman disease (cd) is a rare condition of a benign proliferation of lymph nodes with currently unknown etiology. a 21-year- old male patient referred to the institute with asymptomatic, slowly enlarging, soft tissue mass located on the medial part of the femoral region of his left thigh. magnetic resonance imaging detected a heterogeneous mass of about 132 × 77 × 68 mm^3 in size, which was hypo-signal at t1 and hyper-signal at t2 sequences with central calcification and surrounded by hyperproliferative capillaries. the mass was completely excised through surgery and patient achieved complete remission. in pathologic evaluations, the specimen contained a fibrosclerotic lymph node with a partially distorted structure composed of small-sized mature lymphocytes in a hyper-vascularized stroma without the presence of neoplasia and malignant cells. radiologic and histopathologic findings were suggestive of cd. the patient underwent surgery for excision of tumor and achieved complete remission without any complications.