Spontaneous resolution of multiple nodular pulmonary AA amyloidosis

A 62-year-old man presented with a two-week history of dry cough. A chest computed tomography (CT) showed three nodular masses of soft tissue density without calcification or cavitary formation in the right lung. F-18 fluorodeoxyglucose PET/CT scan revealed high FDG uptake in two out of three pulmonary nodules. Transbronchial lung biopsy specimens consisted of amorphous eosinophilic deposits that were demonstrated to be amyloid because they were positive for Congo Red staining. After oxidation with permanganate solution, the Congo Red staining disappeared, indicating that this amyloid was amyloid A protein-derived type. There was no evidence of any systemic diseases. We diagnosed the patient as having multiple nodular pulmonary AA amyloidosis. The patient was conservatively managed without treatment, and the pulmonary nodules disappeared spontaneously three months later.