A 67-year-old woman with a medical history significant for hypertension, hyperlipidemia, type 2 diabetes mellitus, OSA, and schizophrenia was admitted multiple times the previous 3 months for generalized abdominal pain. Her most recent admission was unique for new onset bilateral upper and lower extremity weakness with paresthesia. Pertinent review of systems included malaise, fever, cough, left lower quadrant pain without weight loss, and rash. Previous evaluation included multiple CT scans of her abdomen that revealed colonic thickening. Ensuing colonoscopy revealed chronic ulcers with cytopathic changes consistent with cytomegalovirus.

A 19-year-old woman presented to pulmonary clinic with recurrent episodes of fevers and productive cough over the last 2 years. She was diagnosed with several episodes of respiratory infection that required antibiotic therapy. Her symptoms improved transiently after antibiotic therapy. However, symptoms continued to recur every 1 to 2 months. She denied any close TB contacts or travel outside the United States. She was a nonsmoker and had no history of immunodeficiency. There was no history of cystic fibrosis or any foreign body aspiration.

A 57-year-old man presented to the ED with a 1-month history of nonproductive cough and shortness of breath. The patient had been in his usual state of health until 2 months before presentation, when he experienced an episode of nonproductive cough and shortness of breath. He was diagnosed clinically with an upper respiratory tract infection; the symptoms resolved after 7 days with conservative therapy alone. One month later, the nonproductive cough and shortness of breath returned. He was treated with a 5-day course of oral azithromycin without any improvement in his symptoms. On presentation to the ED, he denied fever, chills, night sweats, chest pain, arthralgia, myalgia, or hemoptysis. His medical history was significant for hypertension, poorly controlled type 2 diabetes mellitus, and coronary artery bypass grafting. His medications included aspirin, metoprolol, metformin, and glipizide. He denied any history of tobacco, vaping, or recreational drug use. He worked as a cashier in a departmental store and has been doing so for most of his life.

Light chain deposition disease is a rare condition that results in the deposition of light chains in organs and their subsequent dysfunction. It is often the consequence of unchecked light chain production by a plasma cell clone. Rarely does it manifest with solely pulmonary involvement, especially in the young otherwise healthy patient. This article highlights the presentation and diagnosis of pulmonary light chain deposition disease in an active duty solider, the discovery of a plasma cell clone responsible for his symptoms, and the therapy targeted at the plasma cell clone-inducing pulmonary disease. This therapy included a novel successful treatment with an autologous stem cell transplantation. To date, it is among the first such documented successful bone marrow transplantations in treatment of isolated pulmonary light chain deposition disease.