Effective Radiation Therapy for Isolated Apical Pulmonary Amyloidoma: A Case Report and Treatment Insight

BACKGROUND Amyloidosis refers to an assortment of diseases characterized by the accumulation and deposition of misfolded proteins in the extracellular matrix of tissues and organs. It may present systemically, affecting multiple organs, or locally by affecting a single organ. When the lungs or mediastinal structures are involved, the term pulmonary amyloid is used. Sole pulmonary involvement with amyloid is extremely rare. There is no definitive treatment for this disease, but proposed treatment options include surgery, cytotoxic medications, and external beam radiation therapy (EBRT). CASE REPORT A 68-year-old man with a left apical lung mass presented with subacute shortness of breath. Comprehensive evaluation of the patient's symptoms and findings, including infectious and oncologic evaluation, were performed. Infectious evaluation revealed positive acid-fast bacilli sputum cultures with Mycobacterium chimerea intracellulare. Biopsy of the mass revealed a Lambda restricted amyloidoma, which is usually seen in lymphoproliferative diseases and disorders. Bone marrow biopsy did not reveal any monoclonal cell lines or neoplasms. Abdominal fat pad biopsy was performed to rule out systemic amyloid and the results were negative. The diagnosis of isolated apical pulmonary amyloidoma was made. EBRT was performed over 12 fractions in 24 mGy, with improvement in the patient's symptoms. CONCLUSIONS The diagnosis of pulmonary amyloid necessitates comprehensive evaluation. There is no specific treatment for pulmonary amyloid; however, there has been success with surgical intervention, cytotoxic medications, and EBRT. Successful treatment of the amyloidoma is based on its anatomic location. We suggest EBRT in fractionated doses for optimal treatment of rare isolated apical pulmonary amyloidoma.