Diagnostic value of epithelioid cell granulomas in bronchoscopic biopsies

Background: The granulomatous inflammatory response is a manifestation of many lung diseases. Objective: To evaluate the diagnostic value of epithelioid cell granulomas in bronchoscopic biopsies in daily clinical practice. Methods: The data of 157 consecutive patients with epithelioid cell granulomas in biopsy tissue who had undergone the bronchoscopic lung biopsy or bronchial biopsy were examined. All cases were divided into non-necrotizing epithelioid cell granulomas and epithelioid cell granulomas with necrosis. Results: Of all the cases 108 had non-necrotizing epithelioid cell granulomas and 49 had epithelioid cell granulomas with necrosis. Without respect to the presence of necrosis in granulomas, the majority of the patients had sarcoidosis (50%) or tuberculosis (34%). 95% of the patients with sarcoidosis had non-necrotizing epithelioid cell granulomas and the remaining 5% had granulomas with necrosis. The sensitivity of non-necrotizing epithelioid cell granuloma for the diagnosis of sarcoidosis was 95% and specificity 57%. The positive and negative predictive values were 69% and 92%, respectively. Of the patients with culture positive tuberculosis 72% had epithelioid cell granulomas with necrosis and 28% had non-necrotizing epithelioid cell granulomas. The sensitivity of epithelioid cell granuloma with necrosis for the diagnosis of tuberculosis was 72% and specificity 90%. The positive and negative predictive values were 80%, and 86%, respectively. Conclusion: A significant overlap in types of granulomatous inflammation between tuberculosis and sarcoidosis was found. The type of epithelioid cell granuloma alone was not sufficient for the final clinical diagnosis.