Pulmonary Light and Heavy Chain Deposition Disease

Abstract

A 64-year-old man with a history of smoking and asbestos exposure was referred for an F-18 FDG PET/CT, to evaluate multiple growing lung nodules that had been found incidentally on prior chest CTs. The PET/CT showed multiple hypermetabolic nodules in both the lungs, with varying intensity of FDG uptake, raising the suspicion of multifocal malignancy. Wedge resections of the right lung were done to remove the 2 most hypermetabolic nodules, and histologic evaluation revealed pulmonary light and heavy chain deposition disease. A follow-up PET/CT performed 1 year later showed another slowly growing nodule in the left lung with a significant increase in F-18 FDG uptake. Only 22 cases of pulmonary light chain deposition disease have been reported in the literature. This is a report of F-18 FDG uptake in nodules of pulmonary light chain deposition disease. These nodules can grow in size and can show increased F-18 FDG uptake on follow-up studies, mimicking a growing lung malignancy.