Pulmonary light chain deposition disease: a retrospective analysis of 11 cases

Introduction: Light Chain Deposition Disease (LCDD) is a rarely affects the lungs. We aimed to explore the clinical and radiologic manifestations including positron emission tomography (PET) scan, of pulmonary LCDD. Methods: A retrospective, computer-assisted search was performed to identify patients with biopsy-proven pulmonary LCDD seen at Mayo Clinic, Rochester from 1997-2018. Demographic, clinical, and imaging features were analyzed. Results: Among 11 patients with pulmonary LCDD; the median age at the time of diagnosis was 55.1(39.1-77.2) years, 72% were females, and 64% were never smokers. Dyspnea (27%) and chest pain (27%) were the most common respiratory symptoms. Six patients had Sjogren’s syndrome and 2 had sarcoidosis. Eight patients had lymphoma involving the mucosa-associated lymphoid tissue and 1 had multiple myeloma. CT scan of the chest was available for 10 patients; nine (90%) had cysts mostly of lower lung distribution. Round/oval was the predominant shape of the cysts. Fifty-five percent had 1-5 cysts present, 44% had more than 21 cysts. The median diameter of the cyst was 22 mm (range, 5-68);67% of patients had cyst wall thickness of 1 mm. All 10 patients had solid nodules with 40% having >10 nodules. The median diameter of the nodule was 13 mm (range, 6-26). PET scan was available for 9 patients; in 7 patients lung nodules manifested FDG uptake with a median maximum standardized uptake value of 2.0 (range, 1.0-5.9). In the median follow up of 2.4 yr(range, 0.5-9.9);3 patients died. Conclusions: LCDD can affect the lungs in the form of cysts and nodules, especially in the setting of Sjogren’s syndrome.