A case of Sjögren syndrome with pulmonary amyloidosis complicating microscopic polyangiitis.

We present the case of a 71-year-old Japanese woman with Sjögren syndrome complicated with pulmonary amyloidosis who developed microscopic polyangiitis. She was admitted because of fever, weight loss, and paresthesia of the plantae and fingers. Chest computed tomography revealed bilateral multiple nodules with calcification in the lung. Transbronchial lung biopsy specimens showed AL-type (primary) amyloid deposits. The patient also tested positive for myeloperoxidase-antineutrophil cytoplasmic antibodies (MPO-ANCA), with changes in the MPO-ANCA titer that paralleled changes in the symptoms. Nerve conduction velocity findings showed mononeuropathy multiplex. Livedo vasculitis was observed on bilateral lower legs, and skin biopsy showed leukoclastic vasculitis. We diagnosed the patient as having microscopic polyangiitis.