Tuberculosis vs Sarcoidosis
How to tell Tuberculosis and Sarcoidosis apart when a board question makes them look alike.
TB is infectious caseating AFB disease; sarcoidosis is noncaseating multisystem granulomatous disease after excluding infection.
Side by side
TB causes infectious caseating granulomas with cough, fever, night sweats, weight loss, hemoptysis, apical cavitation, acid-fast bacilli, and exposure or immunosuppression risk.
Sarcoidosis causes noncaseating granulomas with bilateral hilar lymphadenopathy, pulmonary symptoms, uveitis, erythema nodosum, hypercalcemia, and elevated ACE in a compatible exclusion-based diagnosis.
Mycobacterium tuberculosis survives in macrophages and triggers Th1-driven granulomatous inflammation with caseous necrosis.
Sarcoidosis is an immune-mediated multisystem granulomatous disease without an identifiable infectious organism.
AFB smear/culture/NAAT, positive IGRA, caseating granulomas, cavitary apical disease, and constitutional infectious symptoms support TB.
Noncaseating granulomas, bilateral hilar adenopathy, hypercalcemia from macrophage 1-alpha-hydroxylase, elevated ACE, and negative infectious testing support sarcoidosis.
The trap
Both can produce granulomas and hilar adenopathy, so AFB/caseation/infectious symptoms versus noncaseating multisystem clues decide.
Watch it explained
Test it nowThe repair move
For granulomatous lung disease, prove or exclude infection before calling sarcoidosis.
Try a free question
CoreA patient has chronic cough, fever, night sweats, weight loss, apical cavitation, caseating granulomas, and acid-fast bacilli on sputum testing. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Tuberculosis. Constitutional symptoms, apical cavitation, caseating granulomas, and acid-fast bacilli support tuberculosis.
Why the other choices are tempting
- B. Sarcoidosis has noncaseating granulomas and requires exclusion of infection.
- C. Hypersensitivity pneumonitis follows antigen exposure and has interstitial inflammation.
- D. Silicosis is occupational pneumoconiosis with upper-lobe nodules and eggshell calcification.
- E. Goodpasture syndrome causes pulmonary hemorrhage and glomerulonephritis.
Flashcards
Tap a card to flip it.
What granuloma type supports tuberculosis?
Caseating granulomas with infectious symptoms or acid-fast bacilli support tuberculosis over sarcoidosis.
What stain result supports tuberculosis?
Acid-fast bacilli on smear or tissue support tuberculosis.
Quick answers
What is the fastest way to tell Tuberculosis from Sarcoidosis?
TB is infectious caseating AFB disease; sarcoidosis is noncaseating multisystem granulomatous disease after excluding infection.
What is the key clue for Tuberculosis?
TB causes infectious caseating granulomas with cough, fever, night sweats, weight loss, hemoptysis, apical cavitation, acid-fast bacilli, and exposure or immunosuppression risk.
What is the key clue for Sarcoidosis?
Sarcoidosis causes noncaseating granulomas with bilateral hilar lymphadenopathy, pulmonary symptoms, uveitis, erythema nodosum, hypercalcemia, and elevated ACE in a compatible exclusion-based diagnosis.
What is the common trap with Tuberculosis vs Sarcoidosis?
Both can produce granulomas and hilar adenopathy, so AFB/caseation/infectious symptoms versus noncaseating multisystem clues decide.