Histopathologic Variability in Usual and Nonspecific Interstitial Pneumonias

• Published in: American journal of respiratory and critical care medicine 2001-11, Vol.164 (9), p.1722-1727
• Main Authors: FLAHERTY, KEVIN R, TRAVIS, WILLIAM D, COLBY, THOMAS V, TOEWS, GALEN B, KAZEROONI, ELLA A, GROSS, BARRY H, JAIN, ARVIND, STRAWDERMAN, ROBERT L., III, FLINT, ANDREW, LYNCH, JOSEPH P., III, MARTINEZ, FERNANDO J
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Biological and medical sciences; Diagnosis, Differential; Female; Humans; Investigative techniques, diagnostic techniques (general aspects); Lung Diseases, Interstitial - mortality; Lung Diseases, Interstitial - pathology; Male; Medical sciences; Michigan - epidemiology; Middle Aged; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Prognosis; Proportional Hazards Models; Pulmonary Fibrosis - pathology; Respiratory system; Survival Rate; Tomography, X-Ray Computed
• ISSN: 1073-449X; 1535-4970
• DOI: 10.1164/ajrccm.164.9.2103074

Findings of surgical lung biopsy (SLB) are important in categorizing patients with idiopathic interstitial pneumonia (IIP). We investigated whether histologic variability would be evident in SLB specimens from multiple lobes in patients with IIP. SLBs from 168 patients, 109 of whom had multiple lobes biopsied, were reviewed by three pathologists. A diagnosis was assigned to each lobe. A different diagnosis was found between lobes in 26% of the patients. Patients with usual interstitial pneumonia (UIP) in all lobes were categorized as concordant for UIP (n = 51) and those with UIP in at least one lobe were categorized as discordant for UIP (n = 28). Patients with nonspecific interstitial pneumonia (NSIP) in all lobes were categorized as having fibrotic (n = 25) or cellular NSIP (n = 5). No consistent distribution of lobar histology was noted. Patients concordant for UIP were older (63 +/- 9 [mean +/- SD] yr; p < 0.05 as compared with all other groups) than those discordant for UIP (57 +/- 12 yr) or with fibrotic NSIP (56 +/- 11 yr) or cellular NSIP (50 +/- 9 yr). Semiquantitative high-resolution computed tomography demonstrated a varied profusion of fibrosis (p < 0.05 for all group comparisons), with more fibrosis in concordant UIP (2.13 +/- 0.62) than in discordant UIP (1.42 +/- 0.73), fibrotic NSIP (0.83 +/- 0.58), or cellular NSIP (0.44 +/- 0.42). Survival was better for patients with NSIP than for those in both UIP groups (p < 0.001), although survival in the two UIP groups was comparable (p = 0.16). Lobar histologic variability is frequent in patients with IIP, patients with a histologic pattern of UIP in any lobe should be classified as having UIP.