Comparison of clinicopathologic features and prognosis between idiopathic nonspecific interstitial pneumonia and usual interstitial pneumonia

Abstract

Objective To investigate clinicopathologic features and prognosis of idiopathic nonspecific interstitial pneumonia（INSIP）, and its differential diagnosis from usual interstitial pneumonia（UIP）. Methods Analysis was made on 21 INSIP patients and 18 UIP patients with biopsy-proven by open or video-assisted thoracoscopic lung biopsy. Clinical, pathological findings and follow-up information of the patients were reviewed. Results INSIP was more common in female and clinical manifestations were nonspeeific. High- resolution computed tomography（HRCT） demonstrated ground-glass, net and patchy attenuation in lung. Pathological characteristics showed a heterogeneous appearance. According to pathological characteristics, INSIP was separated into cellular, fibrosing and mixed patterns. The cellular INSIP, fibrosing INSIP and UIP had a mean age of 48 and 60,respectively. The frequencies of fibroblast foci,muscle sclerosis, honeycombing change and pulmonary architectural destruction of INSIP and UIP were 19.05% and 100% （ P 〈0. 001）, 19.05% and 88.89%P 〈0.05）,23.81% and 94.44%（P 〈0.01）,33.33% and 100%（P 〈0.01）, respectively. Response to glucocorticoid and prognosis were significantly better in INSIP patients than in UIP patients. Conclusions INSIP is not easily differential from UIP in the general clinical manifestations. HRCT is helpful for the differential diagnosis of cellular INSIP and UIP. The definite diagnosis of INISP depends on open lung biopsy. Key words: Idiopathic nonspecific interstitial pneumonia; Usual interstitial pneumonia; Clinico- radiologie-pathology; Diagnosis