Histopathologic Characteristics of Granulomas Associated with Lung Malignancies: A Retrospective Study
JB Placido, VB Reddy, AJ Patel, AW Kim, M Liptay, P Gattuso. Rush University Medical Center, Chicago, IL
Background: Sporadic reports in the literature identify the coexistence of noncaseating granulomas (sarcoid-like pattern) with hematologic malignancies as well as with solid tumors, including lung. We undertook a retrospective study of 128 cases of lung granulomas to assess the incidence as well as the histologic type of granulomas that coexist with malignancies.
Design: Review of our surgical pathology records from 1996 to 2008 identified 128 lung specimens with granulomas. The following characteristics were reviewed: Age, sex, histologic type of granulomas, and coexistance of granulomas with tumors.
Results: A total of 128 patients with lung granulomas were recorded. Seventy were female and 58 were male. The age ranged from 24 to 89, with a mean age of 59 years. Seventy-three granulomas were necrotizing, and 55 were not necrotizing. Forty-seven (36.7 %) out of 128 cases showed microorganisms (31 histoplasma, 8 aspergillus, 4 coccidioides, and 4 blastomyces). Thirty-seven (28.9 %) cases were associated with lung malignancies (19 adenocarcinomas, 7 squamous cell carcinomas, 3 carcinoids, 2 large cell carcinomas, 1 small cell carcinoma and 5 metastatic tumors). In this group of patients, 17 had caseating granulomas and 20 had noncaseating granulomas (12 calcified, 3 hyalinized, and 5 with sarcoid-like pattern). Nine (24.3%) of these cases showed microorganisms (8 histoplasma, 1 blastomyces).
Conclusions: 1. Thirty-seven (28.9 %) cases of lung granulomas were associated with malignancies. 2. The most common malignancy associated with granulomas is adenocarcinoma-- 19 (51.3 %) cases. 3. Nine (24.3 %) out of 37 cases of granulomas associated with malignancy showed microorganisms (8 histoplasma, 1 blastomyces). 4. Of the different histologic subtypes of granulomas associated with tumors, the least common was a sarcoid-like reaction (5 cases). 5. The presence of sarcoid-like reaction may represent a local immune response to tumor cells and could play an important role in the host defenses against metastatic spread. 6. The association of granulomas with malignant lung tumors poses a challenge for clinicians in differentiating granulomas versus tumor spread. Tissue biopsy is still needed in the majority of the cases to confirm the diagnosis. 7. An unusual finding is that none of the granulomas in our series was associated with mycobacterial infection.
Monday, March 9, 2009 1:00 PM
Poster Session II # 196, Monday Afternoon