Epithelioid Cell Granuloma Detection in the Sputum of Patients with Pulmonary Tuberculosis

Abstract

Background: Epithelioid cell granulomas (ECG) are evident in the histology of various pulmonary diseases, including pulmonary tuberculosis (PTB); however, the diagnostic value of ECG in sputum cytology for patients with granulomatous lung diseases is unclear. Methods: To evaluate the value of identifying ECG in the sputum of patients with PTB and other respiratory diseases, we retrospectively reviewed the cytology database and clinical profiles of patients admitted to our department between 2003 and 2011. Results: Of the 11,782 patients examined by sputum cytology, ECG was detected in the cytology specimens of 32 (0.3%) patients. Thirty-one of these patients had PTB, and the remaining patient had pulmonary nontuberculous mycobacteriosis (PNTM). There were no ECG-positive cases among patients with other respiratory diseases, with the exception of one patient with comorbid lung cancer and PTB. The incidence of ECG was significantly higher in PTB (0.8%, 31/3716 cases) than in PNTM (0.09%, 1/1117 cases, P>0.05). Langhans giant cells with (2 cases) and without (5 cases) necrosis was detected only in PTB specimens. Clinical findings in the PTB cases included cavities (68%) on radiography and positive sputum smear for acid-fast bacilli (90%); the PNTM case also showed cavity and smear-positive sputum. Conclusion: In our population of patients with various respiratory diseases, the existence of ECG in sputum cytology was rare and limited to pulmonary mycobacteriosis, particularly PTB. We suggest ECG detection is a useful aid for diagnosing unsuspected and infective PTB, and is associated with disease severity.