Tuberculosis Beyond the Lungs: Extrapulmonary TB Sites and Manifestations

While pulmonary TB is most common, Mycobacterium tuberculosis can disseminate hematogenously to virtually any organ. Extrapulmonary TB (EPTB) accounts for 15–20% of TB cases (higher in HIV, children, immigrants).

Common Extrapulmonary Sites & Presentations

1. Lymph Nodes (Tuberculous Lymphadenitis)

Most common EPTB. Cervical nodes (scrofula) — painless, matted, may suppurate/fistulize. Also axillary, inguinal, mediastinal, abdominal.

2. Central Nervous System (Tuberculous Meningitis / Tuberculoma)

Most severe. Subacute headache, fever, cranial nerve palsies, altered mental status, hydrocephalus. Tuberculomas: space-occupying lesions causing seizures, focal deficits. High mortality without early treatment.

3. Pleura (Tuberculous Pleuritis)

Exudative pleural effusion (lymphocytic, high ADA, low glucose). May cause pleuritic pain, dyspnea. Can progress to fibrothorax.

4. Pericardium (Tuberculous Pericarditis)

Pericardial effusion → tamponade (emergency). Constrictive pericarditis (late). Chest pain, dyspnea, paradoxical pulse, muffled heart sounds.

5. Genitourinary (Renal/Bladder/Genital TB)

Sterile pyuria, hematuria, flank pain. Strictures, calcifications, infertility. Epididymo-orchitis in men; endometrial/tubal involvement in women.

6. Musculoskeletal (Pott's Disease / TB Arthritis)

Spine (Pott's): Thoracolumbar > lumbar. Vertebral collapse, gibbus deformity, cord compression (paraplegia). Joints: Hip, knee — monoarticular, indolent.

7. Abdominal TB

Peritoneum (ascites, doughy abdomen), ileocecal region (mass, obstruction), solid organs (liver, spleen). Mimics Crohn's, malignancy.

8. Skin (Cutaneous TB)

Lupus vulgaris, scrofuloderma, TB verrucosa cutis — rare, usually secondary to contiguous spread or hematogenous.

Key Points

• EPTB can occur without active pulmonary TB (up to 50% have normal CXR).
• Diagnosis: Tissue biopsy (histology: caseating granulomas, AFB stain, culture, PCR/Xpert MTB/RIF).
• Treatment: Same 4-drug regimen (HRZE) as pulmonary TB; duration often 9–12 months for CNS/bone.
• Corticosteroids adjunct for meningitis, pericarditis, airway obstruction.

High index of suspicion needed — EPTB is a great mimicker. Multidisciplinary management improves outcomes.