[Autopsy case of amyloidosis with marked cardiac and pulmonary lesions associated with myeloma, initially presenting with muscle weakness].

A 69-year-old man presented initially with muscle weakness of the bilateral lower limbs. Chest roentgenogram showed diffuse reticulonodular shadows, bilateral hilar lymphadenopathy, and dullness of bilateral costophrenic angles. Chest CT showed thickening and irregularity of vascular shadows, and thickening of bronchial walls. On the first admission we could not diagnose pulmonary or muscle lesions. He was subsequently admitted for the deterioration of congestive heart failure, but there was no improvement. Myocardial biopsy demonstrated deposition of amyloid in the cardiac muscular tissue. Autopsy revealed amyloid deposition in pulmonary vasculature, alveolar septal walls and pleura. Amyloid deposition was also recognized systemically in skeletal muscles, lymph nodes, liver, kidney, spleen, stomach, and intestines. We recognized about 20% IgA lambda-positive plasma cells with atypia, and myeloma-associated amyloidosis diagnosed. This case was classified as diffuse alveolar septal form and pleural form of pulmonary amyloidosis. We could find only a few reports of pleural form, which exhibits an interesting distribution.