Disseminated tuberculosis


Miliary tuberculosis is a widespread form of the disease as a result of hematogenous spread of Mycobacterium tuberculosis.  It is classically referred to miliary pulmonary tuberculosis which usually appears as miliary pulmonary nodules and pleural effusion on chest radiographs and on CT scans. There can be associated or isolated Extrapulmonary Tuberculosis as a result of this hematogenous spread of the disease, classically appearing widespread TB granulomas of the affected organ/organs. However certain forms of the disease exist manifesting with specific findings such as TB affection of the CNS (TB meningitis and TB meningoencephalitis) and tuberculous spondylitis (Pott Disease).

It is more common to occur in individuals of lower socioeconomic status. In many cases, such as the one in hand, the presentations of pulmonary TB can be subtle and nonspecific and the patient can present later by extrapulmonary affection which can happen in a wide range of organs. However pulmonary TB is usually present in the post-primary form, which can present in variable forms depending on the severity ranging from scattered reticulonodular opacities, cavitary lesion or widespread miliary TB nodules and pleural disease. 

TB granulomas can affect many organs including the brain, where it present as ring-enhancing parenchymal lesions that have to be differentiated from other ring-enhancing lesions, however the presence of meningeal involvement narrows the differential diagnosis. TB granulomas can also affect, as in our case, variable abdominal organs such as the liver, spleen and kidneys, and can result in variable degrees of organ dysfunction depending on the severity of the disease. 

Osseous involvement is another consequence of hematogenous spread of tuberculosis, in addition there may be spinal disease or TB spondylodiscitis resulting in abscess formation and the classical Pott disease. Cross-sectional imaging can clearly show the extent of the affected vertebrae and the related paraspinal or epidural fluid collection.