Causes of Granulomatous Inflammation in Lung Biopsies and Resections from Diverse Geographic Settings: An International, Multi-Institution Retrospective Study of 500 Cases.
Sanjay Mukhopadhyay, Carol Farver, Laszlo T Vaszar, Owen J Dempsey, Helmut H Popper, Haresh Mani, Vera L Capelozzi, Junya Fukuoka, Keith M Kerr, E Handan Zeren, Venkatesh K Iyer, Tomonori Tanaka, Ivy Narde, Angheliki Nomikos, Derya Gumurdulu, Sudheer Arava, Dani S Zander, Henry D Tazelaar. State University of New York Upstate Medical University, Syracuse; Cleveland Clinic, OH; Mayo Clinic, Scottsdale, AZ; Aberdeen University Medical School, United Kingdom; Medical University of Graz, Austria; Penn State Milton S. Hershey Medical Center, Hershey, PA; University of São Paulo, Brazil; Toyama University Hospital, Japan; Çukurova University, Adana, Turkey; All India Institute of Medical Sciences, New Delhi, India; Acibadem Health Group, Istanbul, Turkey
Background: Despite the central role of histology in the diagnosis of pulmonary granulomas, there is little data regarding the full spectrum of causes of granulomatous lung disease in pathologic specimens. The aims of this study were to identify the causes of pulmonary granulomas and their incidence in pathologic specimens, to determine whether these causes vary by geographic location, and to ascertain the proportion of cases of unknown etiology.
Design: Lung biopsies (467) and resections (33) showing granulomatous inflammation (n=500) were reviewed retrospectively by pathologists from 10 institutions (4 from the United States [US] and 1 each from Brazil, Scotland, Austria, Turkey, India and Japan). Fifty consecutive cases from each location were classified by diagnosis, incorporating clinical and microbiologic data where available.
Results: Specific diagnoses were made in 58% (290/500); the most common were sarcoidosis (136/500, 27%) and infections (125/500, 25%). Nearly all infections were mycobacterial (n=72) or fungal (n=51). Mycobacteria were identified in 19% cases (56/300) outside the US vs. 8% (16/200) within the US. In contrast, fungi accounted for 19% cases (38/200) in the US vs. 4% (13/300) in other locations. In 42% of all cases (210/500; 85 necrotizing, 125 non-necrotizing), a definite etiology could not be determined.
Conclusions: This is the largest and most geographically inclusive study of granulomatous lung disease to date. Across several geographic settings, sarcoidosis and infections are the most common causes of granulomatous lung disease diagnosed in pathologic specimens. Infectious causes of granulomatous lung disease show geographic variation, in that fungi are more commonly identified than mycobacteria within the US, whereas the reverse is true in other countries. A definite etiology cannot be demonstrated in more than a third of all cases of granulomatous inflammation diagnosed on lung biopsies and resections.
Wednesday, March 2, 2011 9:30 AM
Poster Session V # 269, Wednesday Morning