Imaging of tuberculosis of the abdominal viscera: beyond the intestines.

Dear Editor,

This is with regards to an article titled “Imaging of tuberculosis of the abdominal viscera: Beyond the intestines,” published in your journal.[1] We read the article with interest and have the following comments to offer.

The statement made by the authors, that “genitourinary tuberculosis has been reported to be the most common site for extrapulmonary tuberculosis” is incorrect.

The reference cited by the authors is from a retrospective analysis of 397 patients in Turkey. Data from the larger population based studies do not support this assertion. Surveillance studies from the US and Europe reveal the largest proportion of extrapulmonary tuberculosis cases is lymph node (37.2% and 30.5%) and pleural tuberculosis (16.9% and 36.7%).[23] Pleura (60%) and lymph node (14%) are the major sites of extrapulmonary disease in East Africa.[4] In India, which has a third of world's tuberculosis cases, lymph node tuberculosis is the most common form of extrapulmonary tuberculosis.[5]

Genitourinary tuberculosis comprises 6.9%, 5%, and less than 5% of all extrapulmonary tuberculosis cases in Europe, US, and Africa/India respectively.[345] Regarding the high frequency of genitourinary tuberculosis, the authors have cited studies that refer to a survey of extrapulmonary tuberculosis by Farer et al., in 1979 during the pre-acquired immunodeficiency syndrome (AIDS) era.[6] In subsequent years, AIDS related immunosuppression in patients, led to dissemination to different organ systems and a decline in the relative frequency of genitourinary tuberculosis.[7]

We thank Dr. Karmakar for his valuable comments on our article. While we agree with the fact that lymph node and pleura are the most common site of tuberculosis outside the lungs, we would like to emphasize the fact that the comment made in our article was in the context of extra-thoracic tuberculosis in general and solid abdominal visceral tuberculosis in particular. Though the semantics of the comment can be dwelled upon in depth, our intention was to highlight the significance of solid visceral tuberculosis in the abdomen.