Asymptomatic Miliary Tuberculosis in a Patient With Polymyalgia Rheumatica

Miliary tuberculosis (TB), a severe form of TB caused by lymphohematogenous dissemination from a Mycobacterium tuberculosis focus, usually presents with systemic symptoms including fever and malaise. Here, we report the case of an 87-year-old woman treated with low-dose prednisolone and methotrexate for polymyalgia rheumatica, incidentally diagnosed with small miliary nodules in her lungs on chest computed tomography without any symptoms. Moreover, the patient reported being full of energy. The acid-fast bacterial culture and polymerase chain reaction test from various sites, including the transbronchial lung biopsy (TBLB) and bronchoalveolar lavage fluid, were negative; however, the histology of the TBLB specimen revealed epithelioid granuloma without acid-fast bacteria. One and a half months later, she was admitted to our hospital with fever and somnolence. The cerebrospinal fluid culture test was positive for Mycobacterium tuberculosis, and the patient was diagnosed with miliary TB complicated by tuberculous meningitis. This report suggests that although systemic symptoms usually accompany miliary TB, patients can be asymptomatic, and careful follow-up is important when suspected.