Objective: To highlight a rare but important cause of cystic lung disease.

Case: A 67-year-old female was incidentally found to have bilateral lung nodules on a CT angiogram of the head and neck while undergoing investigation for a posterior inferior cerebellar artery (PICA) stroke. She had no respiratory symptoms and was an ex-smoker, having quit 37 years previously and had a 15-pack-year history. Lupus anticoagulant was positive on subsequent thrombophilia screen. A CT chest demonstrated bilateral lung nodules (range 5-30 mm) in a random distribution and bilateral thin-walled cysts (range 4-20mm), with vessels traversing both cyst wall...

Background: Light chain deposition disease (LCDD) is arare disease entity characterized by immunoglobulin light chain deposition in the tissues.It was first described by Randall in 1976.(1)It is predominantly a multi-system disease, affecting the kidneys in over 90% of patients. The liver, heart and lungs can also be affected.(2)Rarely it is found to solely manifest as pulmonary disease. Theprevalence of pulmonary LCDD is unknown.Since 1987, approximately 50 cases have been reported where the disease burden is isolated to the lung.(3) The majority of cases are inicidentally...

Pulmonary light chain deposition disease is a rare but important cause of cystic lung disease and is often incidentally found, as it was in this case. The finding of bilateral pulmonary cysts, often with vessels traversing the cyst wall or through the cyst itself, and pulmonary nodules raises the possibility of light chain disease. Patients can have a background of alymphoproliferative disorder, MALT lymphoma or Sjögren’s Syndrome, but many cases are also idiopathic.

Randall RE, Williamson WC, Jr., Mullinax F, Tung MY, Still WJ. Manifestations of systemic light chain deposition. Am J Med 1976;60(2):293-299. doi: 10.1016/0002-9343(76)90440-x Kuypers DRJ, Gertz MA. Light-chain deposition disease. Oxford Textbook of Clinical Nephrology: Three-Volume Pack: Oxford University Press, 2015; p. 0. Sweet DE, Wheeler CA, Kearns C, Marquis KM. Pulmonary Light-Chain Deposition Disease. RadioGraphics2022;42(5):E145-E146. doi: 10.1148/rg.220123 Sheard S, Nicholson AG, Edmunds L, Wotherspoon AC, Hansell DM. Pulmonary light-chain deposition disease: CT and pathology findings in nine patients. Clin Radiol 2015;70(5):515-522. doi: 10.1016/j.crad.2015.01.002 Bhargava...