F-18 Fluorodeoxyglucose Positron-Emission Tomography-Computed Tomography in a Case of Extensive Multi-Organal Extranodal Lymphoma with Cardiac Involvement Mimicking Apical Hypertrophic Obstructive Cardiomyopathy: Staging and Response Evaluation

18F fluorodeoxyglucose positron-emission tomography/computed tomography (18F-FDG PET/CT) is a standard imaging tool in staging as well as response evaluation for lymphoma. Here, we present a young male with extensive extranodal lymphoma with cardiac involvement which presented as diffuse myocardial lesion mimicking hypertrophic obstructive cardiomyopathy. 18F-FDG PET/CT helped in the staging by revealing multiple systemic involvements. Interim PET after three cycles of chemotherapy showed a complete metabolic response to therapy in all the extranodal sites including the cardiac involvement, thus retrospectively confirming the lymphomatous involvement. Previous literature also conforms to the superior role of 18F-FDG PET/CT in the clinical management of extensive extranodal lymphoma.