Development of intracerebral hemorrhage in the short-term clinical course of a patient with microscopic polyangiitis without neurological symptoms at diagnosis: an autopsy case.

A 77-year-old man with high-grade fever, progressive renal dysfunction, high serum level of C-reactive protein and positive serum myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) was diagnosed with microscopic polyangiitis with rapidly progressive glomerulonephritis, and remission induction treatment with glucocorticoids and intravenous cyclophosphamide was initiated. Although his general condition improved in a short time, intracerebral hemorrhage occurred 12 days after the initiation of treatment and emergent hematoma evacuation was performed. However, he passed away on day 14. Surprisingly, even though no clinical findings for any organs except for renal involvement was detected before his death, autopsy revealed necrotizing vasculitis affecting various systemic organs including kidney, pancreas, liver, myocardium in ventricle, adipose tissue of the left adrenal gland, small intestine, gallbladder, bronchus, prostate, testis and spleen. It is difficult to detect widespread vasculitis without clinical symptoms and signs in patients with ANCA-associated vasculitis. A whole body assessment tool is necessary to detect unexpected vital organ damage, including cerebral vessels.