Atypical radiological images of pulmonary tuberculosis in 192 diabetic patients: a comparative study

Abstract

Setting: Comparative studies of pulmonary tuberculosis images in diabetics have yielded conflicting results.

Objective: To assess radiological images of pulmonary tuberculosis in a large population of diabetic patients.

Design: Radiographs from in-patients admitted with pulmonary tuberculosis and diabetes (TBDM group, n = 192) were reviewed and compared with a control group of patients with pulmonary tuberculosis alone (TB group, n = 130).

Results: Both groups had a similar evolution time of tuberculosis (approximately 2 years). Statistical differences were observed as follows: TBDM patients were older (51.3+/-0.9 vs. TB group 44.9+/-1.8 years, mean +/- SEM), and had a decreased frequency of upper (17% vs. 56%), and an increased frequency of lower (19% vs. 7%) and upper + lower (64% vs. 36%) lung field lesions. More TBDM patients developed cavitations (82% vs. 59%) more often in the lower lung fields (29% vs. 3%). More multiple cavities were seen in TBDM patients (25% vs. 2%). TBDM group had a lower total leukocyte count (8836.7+/-219.5 vs. 10013.1+/-345.2 cells/mm3), mainly due to a lower number of non-lymphocyte cells (6815.8+/-221.8 vs. 8095.7+/-321.9 cells/mm3). Multiple logistic regression showed that being a diabetic patient was the most important factor determining lower lung field lesions and cavities.

Conclusions: This study in a large number of diabetics with pulmonary tuberculosis confirmed that their chest X-ray images significantly depart from the typical presentation. Clinicians must keep this in mind to avoid misdiagnosis.