Extrapulmonary Tuberculosis

High-Yield Points

Definition and Epidemiology

Pathogenesis

Sites and Clinical Features

Site Clinical features Key diagnostic pointers

Lymph node Painless, firm, matted cervical nodes; may become FNAC and Xpert Ultra; caseating granuloma on (commonest, ~35–40%) fluctuant and form a collar-stud abscess or cytology/histology; excision biopsy if FNAC discharging sinus (scrofula) inconclusive Pleural Fever, pleuritic pain, dyspnoea; usually a unilateral Lymphocyte-predominant exudate; ADA >40 exudative effusion IU/L; low smear yield; pleural biopsy gives the highest yield Abdominal (peritoneal, Ascites, pain, subacute obstruction, doughy abdomen; Ascitic ADA >39 IU/L, SAAG <1.1; CT abdomen; intestinal, nodal) ileocaecal disease mimics Crohn's and caecal colonoscopic or laparoscopic biopsy carcinoma Osteoarticular (spine = Back pain, gibbus deformity, cold abscess, paraparesis; MRI spine — disc-space narrowing with anterior Pott's disease, ~50% of commonly thoracolumbar vertebral body destruction and paravertebral skeletal TB) abscess; CT-guided biopsy CNS (meningitis, Subacute headache, fever, vomiting, cranial nerve CSF: lymphocytic pleocytosis, high protein, tuberculoma) palsies (VI, III, VII), altered sensorium, seizures, low glucose, ADA >10 IU/L; Xpert Ultra on hydrocephalus, stroke from vasculitis CSF; contrast MRI shows basal exudates Genitourinary Sterile pyuria, dysuria, haematuria, epididymo-orchitis, Three early-morning urine samples for AFB culture infertility, tubo-ovarian mass and NAAT; IVU/CT showing calyceal distortion or ureteric stricture Pericardial Effusion, tamponade, later constrictive pericarditis Echocardiography; pericardial fluid ADA >40 with raised JVP, ascites and Kussmaul's sign IU/L; pericardial biopsy Miliary / disseminated Prolonged fever, weight loss, hepatosplenomegaly, Millet-seed nodules on chest X-ray/HRCT; choroid tubercles on fundoscopy, pancytopenia bone marrow and liver biopsy with culture; always do lumbar puncture

Diagnosis

Treatment

Site Total duration Notes

Lymph node, pleural, abdominal, 6 months (2HRZE / 4HRE) Extension only for slow or poor response, genitourinary, pericardial individualised CNS TB / tuberculous meningitis 12 months (2HRZE / 10HRE) Use drugs with good CSF penetration; add corticosteroids Osteoarticular / spinal TB 12 months (2HRZE / 10HRE) Surgery for instability, cord compression or failure of medical therapy Disseminated / miliary with CNS involvement 12 months Always examine CSF before deciding duration 17. Adjunctive corticosteroids — one of the three priority recommendations of the Indian Index-TB guidelines (Central TB Division and DGHS, published in the Indian Journal of Medical Research). Steroids are recommended in tuberculous meningitis (dexamethasone, tapered over 6–8 weeks — reduces mortality) and in tuberculous pericarditis (reduces constriction and the need for pericardiectomy). They are not routinely recommended for lymph node or pleural disease.

Latest Updates (2023–Present)

WHO consolidated guidelines updated through 2025 now recommend Xpert MTB/RIF Ultra as the initial diagnostic test for extrapulmonary specimens, including CSF, lymph node aspirate and tissue, replacing smear microscopy as the first test. Sensitivity in extrapulmonary samples is highest in CSF, bone and joint, and cutaneous specimens and in FNA tissue (about 79%), and lowest in pleural fluid.

India’s National Guidelines for Management of Drug-Resistant TB (27 March 2025) and National Guidance on Differentiated TB Care (March 2025) are the current NTEP reference documents; the Central TB Division has also issued a dedicated Training Module on Extrapulmonary Tuberculosis and an EPTB Standard Treatment Workflow. Differentiated TB care formally stratifies patients by severity and risk — identifying the malnourished, elderly and comorbid for intensified support and inpatient care.

TB Mukt Bharat Abhiyan: following the 100-Day TB Mukt Bharat Abhiyan (launched 7 December 2024) across high-burden districts, a further 2026 campaign continues intensified case-finding using portable handheld X-ray with AI-based reading, upfront NAAT, and nutritional support. India's national target for TB elimination remains 2025, five years ahead of the SDG target of 2030.

Shorter regimens: WHO conditionally recommends a 6-month intensified regimen for tuberculous meningitis as an alternative to the standard 12 months in patients without drug resistance; BPaLM is now the preferred 6-month all-oral regimen for MDR/RR-TB, adopted by NTEP in 2024 — but excluding CNS, osteoarticular and disseminated disease.

Persisting quality gap: a 2025 multicentric Indian cohort found that 76% of EPTB diagnoses were made clinically or radiologically without microbiological confirmation, and only 29% had histopathological confirmation, despite NTEP guidance — a direct reflection of barriers in tissue sampling and processing, and a legitimate point of criticism to raise in a viva.

Current Practice Update

Current evidence and NTEP practice (2023– Issue Textbook position (Pathy's 6e)

2026)

Initial diagnostic test AFB smear and culture remain the gold Culture remains the reference standard, but standard; no clear evidence that detection rates Xpert Ultra is the recommended initial test are lower in the elderly on all extrapulmonary specimens Value of IGRA "Not extensively documented" for active TB in the Position unchanged and now explicit: IGRA and very old TST must not be used to diagnose or exclude active TB Drug-resistant disease Not addressed for extrapulmonary sites All-oral 6-month BPaLM for eligible MDR/RR-TB (NTEP 2024); not for CNS, bone or disseminated disease Duration for CNS and bone TB Not specified 12 months standard; WHO now offers a conditional 6-month intensified alternative for TB meningitis Adjunctive steroids Not addressed Index-TB: recommended in TB meningitis and pericarditis, not routinely elsewhere Programme support Not applicable Ni-kshay Poshan Yojana raised to ₹1,000/month (Nov 2024); mandatory Nikshay notification; differentiated TB care Examiner's Tip Anchor the answer on one sentence: "Extrapulmonary TB is paucibacillary, so tissue is the issue — every accessible site must be sampled for smear, culture and Xpert Ultra together." Then guarantee marks with numbers: ADA cut-offs (pleural 40, ascitic 39, pericardial 40, CSF 10 IU/L), durations (6 months, extended to 12 for CNS and bone), and the two indications for steroids (meningitis and pericarditis). Add the Pathy's geriatric line — "older patients report less fever, sweating and haemoptysis, present more often with dyspnoea, and cavitate less often" — and the clinical rule from Essentials of Clinical Geriatrics: "suspect tuberculosis when an older patient is inexplicably failing." Finish with the programme detail (Nikshay notification, Ni-kshay Poshan Yojana ₹1,000/month) that shows you practise in India.

Extra Points to Remember — Common Sub-Questions

"Cold abscess" — a tuberculous abscess without the classical signs of acute inflammation (no heat, no redness, minimal pain), typical of spinal and lymph node disease. It tracks along fascial planes and may present far from its origin (psoas abscess presenting in the groin).

Pott's spine — classic radiological triad: disc-space narrowing, anterior vertebral body destruction with wedging (gibbus), and paravertebral soft-tissue shadow. Relative preservation of the disc early on distinguishes it from pyogenic spondylodiscitis; skip lesions are characteristic.

Tuberculous meningitis staging (British MRC): Stage I — conscious, no neurological deficit; Stage II — conscious with deficit or GCS 11–14; Stage III — GCS <10 or dense deficit. Outcome correlates directly with the stage at which treatment starts, which is why empirical treatment must not await confirmation. Lymph node TB vs lymphoma vs metastasis in an older patient: TB nodes are matted with caseation on FNAC; lymphoma nodes are rubbery, discrete and require excision biopsy for architecture; metastatic nodes are hard and fixed with a primary elsewhere. Never rely on FNAC alone to exclude lymphoma — excision biopsy is required. Drug-induced hepatitis: stop all hepatotoxic drugs if ALT >3× upper limit with symptoms or >5× without; use a non-hepatotoxic bridging regimen (streptomycin/an injectable, ethambutol, levofloxacin) if treatment cannot be interrupted; reintroduce sequentially once ALT falls below twice normal. Risk is higher in the elderly, the malnourished and in hepatitis B/C carriers — a common combination in Indian practice.

Nursing homes and long-term care: Pathy's and Essentials both call for tuberculosis screening programmes in long-term care facilities, since the older cohort lived through a high-incidence era, was rarely given isoniazid prophylaxis, and reactivates with malnutrition and comorbidity. Screen residents and staff, and remember that outbreak sources may be either.

Appendix — Rapid Revision Grid

Numbers and thresholds most likely to be asked. Read this last on the night before the examination.

Numerical thresholds

Parameter Value

COPD diagnosis Post-bronchodilator FEV1/FVC <0.70 (LLN preferred in the elderly) GOLD spirometric grades 1–4 FEV1 ≥80 / 50–79 / 30–49 / <30 % predicted GOLD Group E (2026) ≥1 moderate or severe exacerbation in the past year Symptom cut-offs mMRC ≥2 or CAT ≥10 Eosinophil thresholds for ICS Favour ≥300/µL; avoid <100/µL Normal vs susceptible-smoker FEV1 decline 25–30 mL/year vs >50 mL/year Reversibility indicating asthma >200 mL rise in FEV1; PEF variability >20% NIV threshold in COPD exacerbation pH <7.35 despite maximal therapy Oxygen target in CO2 retainers SpO2 88–92% (94–98% in others)

Respiratory failure PaO2 <60 mmHg (8 kPa) ± PaCO2 >50 mmHg (6.7 kPa)

LTOT indications PaO2 <7.3 kPa, or 7.3–8.0 kPa with polycythaemia, pulmonary hypertension, oedema or nocturnal hypoxaemia LTOT minimum daily use / survival ≥15 hours/day; about 50% survive 3 years Age-adjusted D-dimer (age >50) Age × 10 µg/L (ADJUST-PE, JAMA 2014)

Revised Geneva probability bands Low 0–3, intermediate 4–10, high >10 Minimum anticoagulation after PE 3 months; extended/indefinite if unprovoked or persistent risk factor Pneumonia — absent fever/cough in elderly 30–40% of cases Pneumonia — radiographic clearance Up to 12 weeks in older adults ADA cut-offs in TB Pleural >40, ascitic >39, pericardial >40, CSF >10 IU/L EPTB treatment duration 6 months; 12 months for CNS and osteoarticular disease MMSE and inhaler use <24 predicts a very high risk of inhaler failure Optimal aerosol particle size 1–5 µm Named trials, guidelines and eponyms Name What it established NOTT (1980) and MRC LTOT ≥15 h/day improves survival in hypoxaemic COPD LOTT (2016) No benefit of oxygen in moderate resting or isolated exercise desaturation ADJUST-PE (2014) Age-adjusted D-dimer safely excludes PE in older patients PESI / sPESI Validated short-term mortality prediction in acute PE, including the elderly HI-PEITHO (NEJM 2026) Catheter-directed thrombolysis superior to anticoagulation alone in intermediate-high-risk PE 2026 AHA/ACC PE Guideline Five-tier Clinical Categories A–E; PERTs, LMWH over UFH, DOACs over VKA (all Class 1) BOREAS / NOTUS Dupilumab reduces COPD exacerbations by about 30% in eosinophilic disease METREX / METREO / MATINEE Mepolizumab reduces COPD exacerbations by about 18–21% GOLD 2026 One moderate exacerbation defines Group E; disease activity as a target; biologics; AI chapter FIBRONEER-IPF / FIBRONEER-ILD Nerandomilast (PDE4B inhibitor) slows FVC decline in IPF and progressive pulmonary fibrosis (2025)

INBUILD / SENSCIS Nintedanib in progressive fibrosing ILD and in systemic sclerosis-ILD PANTHER-IPF Triple immunosuppression is harmful in IPF CAPE COD (NEJM 2023) Hydrocortisone reduces mortality in severe community-acquired pneumonia FLORALI (2015) / SOHO (NEJM Early promise of HFNO not confirmed — SOHO found identical 28-day mortality (14.6%) vs 2026) standard oxygen ERS 2022 HFNC guideline HFNO over conventional oxygen and over NIV in hypoxaemic ARF; try NIV first in hypercapnic COPD Index-TB guidelines (IJMR) India's EPTB guidance — Xpert in diagnosis, adjunct steroids, treatment duration BPaLM (NTEP 2024) 6-month all-oral MDR/RR-TB regimen; excludes CNS, bone and disseminated disease ACIP October 2024 (MMWR Jan Pneumococcal conjugate vaccine for all PCV-naive adults from age 50 2025)

BODE index BMI, Obstruction, Dyspnoea, Exercise capacity — validated prognostic index in COPD Langhans giant cell / caseating Histological hallmark of tuberculosis granuloma Pott's disease, gibbus, cold abscess Spinal tuberculosis eponyms S1Q3T3 Classic but uncommon ECG pattern in pulmonary embolism Six lines to carry into every respiratory answer