Pulmonary amyloidosis: Detection with PET-CT

F-18 deoxyfluoroglucose (F-18 FDG) positron emission tomography computed tomography (PET CT) is a sensitive method for diagnosis and follow up of lung cancer and lymphoma. Three patients with pulmonary amyloidosis who underwent PET CT scans are reported. Two cases had increased uptake of FDG. In one, the pathologic diagnosis was an underlying lymphoma. The second was diagnosed as localized pulmonary amyloidoma with positive uptake of FDG. The third case, despite having low-grade lymphoma with associated secondary amyloidosis, did not show uptake of FDG. PET CT scans may be positive in pulmonary amyloidosis. This could be related to the B-lymphocytes producing the light chains with varying degrees of malignant transformation of the cells. We conclude that pulmonary amyloidosis should be added as a possible false-positive when suspecting pulmonary malignancy. Nevertheless, when uptake is highly positive, the possibility of amyloid producing lymphoma should be considered.