Abstract
Four hundred and ninety-six specimens obtained by transbronchial lung biopsy (TBLB) from 205 patients with sarcoidosis were examined microscopically. A histopathological classification of the findings of the specimens obtained by TBLB was submitted. Noncaseating epithelioid cell granulomas were classified into three types: hypertrophic, atrophic, and fibrous and/or hyalinous. The frequency of giant cells and the intensity of perigranulomatous lymphocytic cuffing were divided into three grades.
After lesions caused by the biopsy were excluded, thickening of alveolar septums (AST) were evaluated and classified into cellular or fibrous type when the alveolar area was broader than 400×400 microns. The diffuseness of AST was divided into three grades. Cellular type AST consisted of interstitial infiltration of lymphocytes, histiocytes or other inflammatory cells other than polymorphonuclear neutrophils. Fibrous type AST consisted of an increase in eosinophilic collagenous matrix and fibroblasts in the alveolar septum.
Lung specimens from 71 sarcoidosis patients without steroid treatment before TBLB were examined by five pathologists applying the above histopathological classification. Noncaseating epithelioid cell granulomas were present in 42 patients (59%) and AST was noted in 20 patients (28%).
Among the 42 patients with epithelioid cell granulomas in the specimens obtained by TBLB, AST was observed in 18 patients (43%: cellular type in 9 and fibrous type in 9), whereas only 2 patients (7%: one each cellular and fibrous type) were evaluated positive for AST among 29 patients with no definite epithelioid cell granulomas in those obtained by TBLB (p<0.01).
AST was noted in 9 of 15 patients (60%: cellular type in 5 and fibrous type in 4) when lymphocytic cuffing was around the epithelioid cell granulomas, whereas AST was noted in 9 of 27 patients (33%: cellular type in 4 and fibrous type in 5) when no definite lymphocytic cuffing was around the granulomas.
Eight of 9 patients (89%) with cellular type AST were associated with hypertrophic epithelioid cell granulomas, whereas 5 of 9 patients (56%) with fibrous type AST were associated with those granulomas.
All of the 9 patients with fibrous type AST were associated with atrophic, fibrous and/or hyalinous epithelioid cell granulomas, whereas only 5 of 9 patients (56%) with cellular type AST were associated with those types of granulomas (p<0.05).
