Abstract
Active pulmonary tuberculosis involving the lung parenchyma is typically seen on CT as consolidation, centrilobular nodules with tree-in-bud branching, cavitating lesions, and miliary nodules. However, some atypical CT patterns of granulomatous disease including tuberculosis have been recently described, namely, clusters of nodules without confluence or with confluence. We present a case of a patient who was found to have nonconfluent clusters of micronodules in the right lung with negative sputum culture for tuberculosis. There were also incidental findings of the partial duplex system of the left kidney with mild-to-moderate hydronephrosis in the lower moiety with proximal hydroureter. The urine culture was then positive for mycobacterium tuberculosis; hence, he was commenced on antituberculous medications. A repeated CT scan revealed significant improvement of the aforementioned clusters of micronodules and left hydronephrosis. In the present case, we would like to highlight the atypical appearances of pulmonary tuberculosis in the form of nonconfluent micronodules on HRCT despite negative sputum workup, with the concurrent active genitourinary tuberculosis.
Highlights
On high-resolution computed tomography (HRCT), a lung nodule is defined as well-defined, discrete opacity in the lung parenchyma measuring less than 30 mm
Active pulmonary tuberculosis involving the lung parenchyma is typically seen on CT scan as consolidation, Figure 2: Selected contrast-enhanced CT images of the upper abdomen in coronal and axial planes showing initial (a–d) and posttreatment follow-up (e, f ) scans. e images of the initial scan show moderate hydronephrosis and hydroureter of the left lower moiety system (∗), which are largely resolved in the follow-up scan. ere were no calculi, ureteric mass, or abdominal lymphadenopathy
Another sign which has been described as highly suggestive of active granulomatous process, namely, sarcoidosis and tuberculosis, is the “nodular-reversed halo sign.” e term nodular-reversed halo is used to describe a ring of nodules surrounding an area of ground-glass attenuation [10]. is should be differentiated from the more widely described “reversed halo sign,” an area of ground glass opacity surrounded by a ring of consolidation, which can be due to many nonspecific causes including organizing pneumonia and fungal infections among others [11]
Summary
On high-resolution computed tomography (HRCT), a lung nodule is defined as well-defined, discrete opacity in the lung parenchyma measuring less than 30 mm. The term micronodule is used to describe a very small nodule. A variety of diameters have been used in the past to define a micronodule, it is recommended that the term be reserved for opacity less than 3 mm in diameter [1]. Diffuse nodules or nodular patterns are usually described according to their location in the secondary pulmonary lobules, namely, centrilobular, perilymphatic, or random in distribution, as the distribution may give some diagnostic clues to the underlying pathogenesis of the disease. Ere are other morphological appearances of nodular patterns such as the “Galaxy Sign” that has been described to be characteristic of granulomatous disease[2]. On the other hand, report a patient with a rare and atypical appearance of pulmonary tuberculosis in the form of nonconfluent micronodules on HRCTand highlight the importance of recognizing such morphological nodular pattern
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
