Disseminated tuberculosis without pulmonary involvement mimicking multiple bone metastases

Article information

Korean J Intern Med. 2025;40(6):1068-1069

Publication date (electronic) : 2025 October 31

doi : https://doi.org/10.3904/kjim.2025.085

Hyo-Jin Lee, Seo-Jun Byun, Si-Hyun Kim

Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea

Correspondence to: Si-Hyun Kim, M.D., Ph.D., Division of Infectious Diseases, Department of Internal Medicine, Incheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 56 Dongsu-ro, Bupyeong-gu, Incheon 21431, Korea, Tel: +82-32-280-5891, Fax: +82-32-280-5987, E-mail: ksihyun@catholic.ac.kr, https://orcid.org/0000-0002-6392-0221

Received 2025 March 13; Revised 2025 April 21; Accepted 2025 April 22.

A 32-year-old man without underlying diseases presented to the emergency department with an abrupt onset of gait disturbances and a 4-week history of back pain. The patient was afebrile, and all laboratory findings were normal. Rapid plasma reagin test for syphilis was negative. Whole-spine magnetic resonance imaging revealed an abnormal signal intensity with contrast enhancement at levels T3-T5 and level L3 (Fig. 1), as well as in the right sacral alar portion and left second rib (not shown). However, chest computed tomography (CT) showed no abnormalities in the lung parenchyma, airways, pleura, or lymph nodes. Bone scan suggested bone metastases in the skull, left clavicle, left third rib, and T3-T5 and L3 vertebrae. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/CT showed intense FDG uptake in multiple bone lesions and portocaval areas, possibly bone metastases and metastatic lymphadenopathy (Fig. 2). Percutaneous transpedicular bone biopsies were performed in the T4 and L3 vertebral bodies. Histopathological findings revealed chronic granulomatous inflammation with necrosis; however, acid-fast bacilli staining and duplex real-time polymerase chain reaction for Mycobacterium tuberculosis complex and non-tuberculous mycobacteria from fresh bone tissue were negative. On the fifteenth day after the biopsy, the mycobacterial culture from the bone specimens tested positive for M. tuberculosis complex.

Figure 1

Sagittal contrast-enhanced fat-suppressed T1-weighted whole-spine magnetic resonance imaging shows abnormal signal intensity with contrast enhancement at levels T3–T5 and L3 with pathologic vertebral body fracture at T4 (white arrows).

Figure 2

Maximal intensity projection image of whole-body ¹⁸F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography shows intense FDG uptake in the T4 vertebral body (maximum standardized uptake value corrected for lean body mass, 14.7) and focal FDG uptake in the left second and third ribs, T1 and L3 vertebral bodies, portocaval and peripancreatic area, right sacral bone, and left iliac bone (red arrows).

M. tuberculosis primarily infects the lungs. However, extrapulmonary tuberculosis (TB) can develop in other organs, including the lymph nodes, liver, spleen, bones, joints, and the central nervous system. Skeletal TB most commonly affects the spine, hips, and knees as a result of the reactivation of hematogenous foci, contiguous disease, or lymphatic spread [1]. Multifocal skeletal TB involving two or more non-contiguous bones is extremely rare and can mimic bone metastases, particularly in the absence of pulmonary involvement. The presence of necrotic lymph nodes increases the likelihood of extrapulmonary TB [2].