[Histopathology of pulmonary tuberculosis]

Although typical histological findings of tuberculosis are well known, the diagnosis of nonmicrobiologically proven tuberculosis with the instruments available to pathology is challenging. Indeed, necrotizing epithelioid cell granulomatosis is typical for tuberculosis, but it is also seen in a number of different infectious or noninfectious lung diseases. The tools of microscopy and molecular pathology are suitable for confirming the diagnosis or paving the way to a differential diagnosis, but molecular pathology applied to formalin-fixated and paraffin-embedded material is limited. This should be openly communicated to the referring clinician. After interdisciplinary re-evaluation of the findings, an alternative solution to confirm the diagnosis must therefore be found if the additional examinations are negative.