A case polymyositis preceded by interstitial pneumonia--proved by open lung biopsy and serial muscle biopsies
Hanawa, M.; Mabuchi, T.; Oeda, H.; Kobayashi, H.; Fujisawa, H.; Sumiyoshi, A.
Nihon Kyobu Shikkan Gakkai Zasshi 19(8): 575-580
1981
ISSN/ISBN: 0301-1542 PMID: 7311213 Document Number: 178644
At 46-yr-old female had nonproductive cough and exertional dyspnea for 1 mo. but no symptoms suggesting collagen disease except occasional sausage digit. The patient was febrile (38.4.degree. C), without muscle weakness and bibasilar Velcro rales were audible. Chest roentgenogram showed coarse linear opacities just above the elevated diaphragm and ground glass appearance in the mid and lower fields of the lungs, indicating interstitial pneumonia (IP), and prednisolone 40 mg was administered. Open lung biopsy was performed and microscopic examination revealed thickening of the alveolar septa with predominant lymphocytic infiltration and fibrosis partially accompanied with honey-combing. There was mucinous type intimal fibrous thickening of the vessels and fibrous thickening of the pleura. These findings suggested the pulmonary complication of collagen disease, especially polymyositis (PM) because of high levels of creatine phosphokinase (CPK), but biopsy of the right rectus femoris muscle revealed no appreciable pathological changes. At 6 mo. later, PM was strongly suspected from her slow movement and the further increase of CPK, but she showed no marked muscle weakness on physical examination. Biopsy of the left deltoid muscle revealed lymphocytic and histiocytic infiltrations in perivascular regions of perimysium, floccular degeneration of muscle fibers, phagocytosis of degenerated muscle fibers and focal proliferation of sarcolemmal nuclei, such as those seen in PM. The IP preceded symptoms of PM. An increase of CPK preceded development of muscle weakness and appearance of histopathological indings in serial muscle biopsies. Sixty-one cases of PM with IP have been reported since 1956, including 12 cases (19.7%) in which the muscular symptoms were not seen within at least 1 mo. after initial diagnosis of IP. Examination for occult muscle disease may be important in patients with chronic IP, as well as examination for pulmonary disease in patients with overt PM.