In 2-6% of primary tuberculosis, massive, lymphohematogenous dissemination of tubercle bacilli results in miliary tuberculosis (MTB). Secondary activation of chronic tuberculosis can also present as MTB. The characteristic radiological findings on chest radiography (CXR) and computed tomography imaging (CT) are innumerable fine nodules. Associated cystic changes are extremely rare.CASE REPORT: An 88-year-old female patient from home presented with cough, fever, lethargy progressing over 2 weeks. She was cachectic, had low-grade fever, and bilateral basal crackles. CXR showed bilateral diffuse nodular opacities and left apical large cavity. Chest CT showed diffuse micronodular lesions, diffuse small cystic changes (image I & II). The picture was consistent with miliary disease. Bronchoalveolar lavage (BAL) was positive for Acid Fast Bacilli staining and transbronchilal biopsy revealed necrotizing granulomatous inflammation. The patient was started on isoniazide, rifampin, ethambutol and pyrazinamide. In three weeks the BAL culture grew Mycobacterium tuberculosis sensitive to all anti-TB agents. A follow up CT scan in 6 weeks showed improvement in the miliary infiltrates, resolution of cystic changes (image III).DISCUSSION: MTB has a wide range of CT findings. In addition to diffuse 1-3 mm micronodules, it also can present as diffuse or localized reticular opacities, ground glass attenuation, air trapping, consolidation, cavitation, fibrosis, lymph nodes enlargement, and septal thickening. MTB is a rare cause of cystic parenchymal changes. We report here an unusual presentation of miliary tuberculosis associated with diffuse cystic changes that were reversible and resolved after six weeks of antituberculous therapy. The differential diagnosis of multiple cystic changes is extensive and includes Pneumocystis carinii infection, lymphangioleiomyomatosis, sarcoidosis, and Langerhans cell histiocytosis among others.
Pulmonary TB in adults is associated with unusual radiographic manifestations for tuberculosis in up to one third of cases. This report further supports atypical radiographic presentation of tuberculosis. In the proper clinical context, clinicians should have a high index of suspicion for tuberculosis in the presence of atypical CT chest findings.
M.I. Najjar, None.