Inflammatory myofibroblastic tumor mimicking a relapse in a patient with Hodgkin's lymphoma: report of an unusual case and review of the literature.

New PET-positive lesions in previously treated patients with lymphomatous malignancies need further investigations. Relapse, sarcoidosis and secondary malignancies are the most important differential diagnosis. Inflammatory myofibroblastic tumors (IMT) is a rare complication after treatment of Hodgkin's disease and every PET-positive lesion should be biopsied to prevent unnecessary intervention.