Benign histiocyte-rich pseudotumor in post treatment mediastinal Hodgkin's lymphoma.

Benign xanthomatous pseudotumors are rare, mass forming lesions composed of lipid laden histiocytes and tumor necrosis following chemotherapy. We present a rare case of young 36 year old male with primary mediastinal Hodgkin's lymphoma who developed xanthomatous pseudotumor mimicking relapse at the site of original disease on positron emission tomography. This scenario places emphasis on histologic confirmation of suspected treatment failure or relapse.