Analysis of chest computed tomography manifestations of non-Mycobacterium tuberculosis induced granulomatous lung diseases

Abstract

PurposeTo analyze the chest computed tomography (CT) manifestations of non-Mycobacterium tuberculosis (TB) induced granulomatous lung disease (GLD) with their clinical presentations and laboratory test results. MethodsA total of 55 patients had chest CT scan during a period from June 2010 to January 2016. We retrospectively compared the location, morphology and other specific features of the lesions that were pathologically diagnosed as non-TB induced GLD. Clinical presentations and laboratory results were also documented. ResultsInfectious causes of GLD identified are mainly pulmonary cryptococcosis (n = 8, 14.5%) and pulmonary actinomycosis (n = 3, 5.5%). For non-infectious causes, the most common cause is pulmonary sarcoidosis (n = 27, 49.1%). Symptoms frequently observed include cough (n = 39, 70.9%) and expectoration (n = 30, 54.4%). Lesions due to GLD are mainly multiple and have bilateral distribution on chest CT. These findings are particularly prominent for non-infectious GLD. Lesions in non-TB induced infectious GLD are often unilateral. The morphology of lung lesions is mostly nodules, but lesions can also be masses, consolidations or ground-glass opacity based on the underlying etiology. Nodules are prominent in lungs affected by sarcoidosis along with thoracic lymphadenopathy. Nodules are also seen in non-TB induced infectious GLD, but they are rarely accompanied by hilar lymphadenopathy. ConclusionChest CT could be helpful in diagnosis of the underlying causes of the disease. Nevertheless, chest CT is still insufficient to provide a diagnosis alone due to its unsatisfactory specificity. Confirmation of the diagnosis still relies on histopathological exam of tissue samples.