A Case of Solitary Amyloid Lung Nodule Treated With Surgery

Primary or light-chain (AL) (lambda) amyloidosis is a rare systemic disorder that is characterized by the misfolding of autologous proteins and the extracellular deposition of abnormally folded proteins composed of immunoglobulin light chains, often caused by plasma cell dyscrasias. We present a unique case of a 57-year-old female with multiple comorbidities, including extensive smoking history and chronic kidney disease, who was incidentally discovered to have a left upper lobe lung nodule on a chest X-ray prompted by complaints of shortness of breath. The patient underwent biopsy of the lung nodule, and by utilizing the gold standard diagnostic technique of a Congo red stain, positive test results confirmed the diagnosis of AL amyloidosis. However, additional investigations, including bone marrow and fat pad biopsies, were negative for plasma cell dyscrasias. The patient subsequently underwent a wedge resection of the nodule, and a follow-up positron emission tomography-computed tomography (PET-CT) scan showed only post-surgical changes in the left upper lobe of the lung without evidence of disease progression or systemic involvement. Given the asymptomatic and multisystem symptomology of most cases, treatment options for AL amyloidosis are individualized. This case discusses pulmonary nodular AL amyloidosis and highlights the diagnostic and treatment options for this disorder.