Microscopic polyangiitis presenting as a "pulmonary-muscle" syndrome: is subclinical alveolar hemorrhage the mechanism of pulmonary fibrosis?

Arthritis Rheum. 2007 Jun;56(6):2065-71. doi: 10.1002/art.22633.


Microscopic polyangiitis (MPA) may present with a syndrome that resembles idiopathic pulmonary fibrosis (IPF). We describe an MPA patient with the clinical presentation of a "pulmonary-muscle" syndrome in which interstitial lung disease antedated the onset of myopathy. Identification of vasculitis on muscle biopsy was instrumental in recognizing clinical, radiographic, and histopathologic features that were more characteristic of MPA than of IPF. Institution of glucocorticoid and cyclophosphamide therapy led to the induction of a complete remission. The histologic findings in this case implicate subclinical episodes of alveolar hemorrhage as the mechanism of interstitial lung disease in MPA.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Biopsy
  • Diagnosis, Differential
  • Female
  • Hemorrhage / complications*
  • Hemorrhage / physiopathology
  • Humans
  • Lung Diseases, Interstitial / pathology
  • Lung Diseases, Interstitial / physiopathology
  • Muscular Diseases / pathology
  • Muscular Diseases / physiopathology
  • Pulmonary Alveoli / pathology
  • Pulmonary Alveoli / physiopathology*
  • Pulmonary Fibrosis / diagnosis
  • Pulmonary Fibrosis / etiology*
  • Pulmonary Fibrosis / physiopathology*
  • Respiratory Muscles / blood supply
  • Respiratory Muscles / pathology
  • Syndrome
  • Vasculitis / diagnosis
  • Vasculitis / pathology
  • Vasculitis / physiopathology*