The relevance of biopsy in tuberculosis patients without human immunodeficiency virus infection

Abstract

Although chronic granulomatous inflammation (CGI) with concomitant caseous necrosis (CN) is a characteristic histological feature of tuberculosis (TB), few studies have investigated its frequency or various pathologic findings. The medical records of 227 human immunodeficiency virus (HIV) -negative, culture-positive TB patients who underwent biopsy were studied. After the frequency of characteristic pathological findings of TB was determined, a pathologist reanalyzed the pathological findings with particular focus on necrosis and reclassified CGI, CN, or possible CN into possible TB pathologic findings. The initial biopsy interpretation revealed that 63 (34.8%) of 181 patients with pulmonary TB had caseating granulomas, 36 (19.9%) patients had only CGI, and 6 (3.3%) patients had only CN. Among 46 patients with extrapulmonary TB, 16 (34.8%) patients had only caseating granulomas, and 14 (30.4%) patients had only CGI. More patients who underwent percutaneous lung biopsy had CGI or CN (76.3%) than patients who underwent transbronchial lung biopsy (53.6%). The reanalysis confirmed all CN cases identified by the first interpretation, and 20 (95.2%) of 21 non-CN cases were reclassified as possible CN. Ten cases (three pulmonary and seven extrapulmonary) were reclassified as possible TB pathologic findings from just necrosis. Caseating granuloma was present in only one-third of TB cases. Even in cases where only necrosis was identified, CN may be present.

Figure 1.

Chronic granulomatous inflammation with central CN (soft tubercle). A rim of epithelioid cells and lymphocytes around the central necrosis is present. Hematoxylin and eosin stain. Scale bar = 100 μm.

Figure 2.

(A) Chronic granulomatous inflammation without central CN (hard tubercle). A collection of Langhans giant and epithelioid cells is visible. (B) Coagulation necrosis composed of devitalized cells and stromal frameworks. (C) Chronic granulomatous inflammation around the fibrinoid necrosis (lower). (D) Chronic granulomatous inflammation around the hyaline change (lower left). Hematoxylin and eosin stain. Scale bar = 100 μm.