Research article

Frequency and predictors of miliary tuberculosis in patients with miliary pulmonary nodules in South Korea: A retrospective cohort study

Sang-Man Jin¹ , Hyun Ju Lee² , Eun-Ah Park² , Ho Yun Lee² , Sang-Min Lee¹ , Seok-Chul Yang¹ , Chul-Gyu Yoo¹ , Young Whan Kim¹ , Sung Koo Han¹ , Young-Soo Shim¹ and Jae-Joon Yim¹

¹Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine and Lung Institute, Seoul National University College of Medicine, 103 Daehangno Jongno-gu, Seoul 110-744, Republic of Korea

²Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, 103 Daehangno Jongno-gu, Seoul 110-744, Republic of Korea

author email corresponding author email

BMC Infectious Diseases 2008, 8:160doi:10.1186/1471-2334-8-160

Published:	26 November 2008

Abstract

Background

Miliary pulmonary nodules are commonly caused by various infections and cancers. We sought to identify the relative frequencies of various aetiologies and the clinical and radiographic predictors of miliary tuberculosis (TB) in patients with miliary pulmonary nodules.

Methods

We performed a retrospective cohort study of patients who presented with micronodules occupying more than two-thirds of the lung volume, based on computed tomography (CT) of the chest, between November 2001 and April 2007, in a tertiary referral hospital in South Korea.

Results

We analyzed 76 patients with miliary pulmonary nodules. Their median age was 52 years and 38 (50%) were males; 18 patients (24%) had a previous or current malignancy and five (7%) had a history of TB. The most common diagnoses of miliary nodules were miliary TB (41 patients, 54%) and miliary metastasis of malignancies (20 patients, 26%). Multivariate analysis revealed that age ≤30 years, HIV infection, corticosteroid use, bronchogenic spread of lesions, and ground-glass opacities occupying >25% of total lung volume increased the probability of miliary TB. However, a history of malignancy decreased the probability of miliary TB.

Conclusion

Miliary TB accounted for approximately half of all causes of miliary pulmonary nodules. Young age, an immune-compromised state, and several clinical and radiographic characteristics increased the probability of miliary TB.