Sunday, December 14, 2008

The many faces of PTB!

Pulmonary tuberculosis may present in many ways. It is also a good mimicker. Often its diagnosis requires thorough investigation to excludes many other differential diagnosis. The most important to exclude is bacterial pneumonia. Despite a full diagnostic work-up, the doctor may fail to establish the diagnosis. He may then empirically start the patient on anti-TB treatment. If there is a response within 2 weeks, he will continue the treatment. Unfortunately, TB treatment carries alot of side effects and the treatment period ranges from 9 months to a year.

What if, if the diagnosis was just bacterial pneumonia? and the doctor miss it. Bacterial pneumonia will also responds to anti-TB treatment and the patient will be on it for 1 full year!!!

There is a 5mm calcified nodule in the left mid-zone. This is calcified granuloma due to previous pulmonary tuberculosis. Similar to its non-calcified counter-part, granulomas contain dormant tubercle bacilli and may be re-activated anytime the body defense system drops.

Note the patchy consolidation with multiple cavitations in the right upper zone. This is typical of active pulmonary tuberculosis.

Different patient but similar presentation - consolidation with cavitations. This is also active pulmonary tuberculosis.

In this patient, the left costo-phrenic angle is blunted. This is due to pleural effusion. A pleural tap should be performed and the fluid sent for AFB test to exclude tuberculosis. There are of course many other causes of pleural effusion but in the right clinical setting, tuberculosis ought to be considered.

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