A patient from North-East India presents with pulmonary cavitary lesions and hepatic nodules. Sputum AFB smear is negative. Biopsy shows caseating granulomas with Langhans-type giant cells and raised ESR. What is the most probable diagnosis?

1. A

   A. Toxoplasmosis

2. B

   B. Tuberculosis

3. C

   D. Sarcoidosis

4. D

   D. Sarcoidosis

Appeared in: INI-CET EXAM -2026

Explanation

• The biopsy finding of 'caseating granulomas with Langhans-type giant cells' is the classic and definitive histopathological feature of Tuberculosis (TB).
• Caseation is a form of necrosis with a cheese-like appearance that is the hallmark of a tuberculous granuloma.
• The presence of both pulmonary cavitary lesions and hepatic nodules suggests a disseminated (miliary) form of TB, where the infection has spread through the bloodstream.
• A negative sputum AFB smear is common in miliary or extrapulmonary TB because the bacterial load in the sputum can be very low (paucibacillary). Diagnosis in such cases relies on biopsy and other tests.

Why Other Options Were Wrong

• Option A: Toxoplasmosis is a parasitic infection that typically causes non-caseating granulomas.
• Option C: Histoplasmosis is a fungal infection. While it can cause granulomas that mimic TB, they are typically non-caseating.
• Option D: Sarcoidosis is definitively characterized by the presence of non-caseating granulomas. The finding of caseation in the biopsy rules out this diagnosis.

Related Visual

Clinical Relevance

• Nursing practice connection: Use the key finding related to Diagnosis of granulomatous diseases based on histopathological findings to guide bedside assessment, documentation, and the next nursing action.
• Nurses must understand that a negative sputum smear does not exclude TB, especially when clinical and radiological suspicion is high. Patient isolation precautions may still be necessary pending further results.
• This case highlights the importance of histopathology (biopsy) in diagnosing TB when standard tests are negative or in cases of extrapulmonary disease.
• In India, under the National Tuberculosis Elimination Program (NTEP), confirmed TB patients are started on Directly Observed Treatment, Short-course (DOTS) to ensure adherence and prevent drug resistance.

How to Approach the Question

• This is an analytical question requiring interpretation of clinical and laboratory data.
• First, identify the most specific and definitive finding in the question stem. Here, it is the biopsy result: 'caseating granulomas with Langhans-type giant cells'.
• Recall that caseating granulomas are the pathognomonic (hallmark) feature of Tuberculosis.
• Evaluate the other findings in light of this primary diagnosis. Pulmonary cavities and hepatic nodules are consistent with disseminated (miliary) TB. A negative sputum smear is a known feature of paucibacillary or extrapulmonary TB and does not rule it out.
• Systematically rule out the other options based on the key finding. Sarcoidosis is characterized by non-caseating granulomas. Toxoplasmosis and Histoplasmosis have different typical presentations and pathology.

Concept Tested & Keywords

• Concept Tested: Diagnosis of granulomatous diseases based on histopathological findings.
• Stem keywords: pulmonary cavitary lesions, hepatic nodules, sputum AFB smear is negative, caseating granulomas, Langhans-type giant cells
• Lead-in keywords: most probable diagnosis
• Clinical cues: The biopsy result of 'caseating granulomas' is the most definitive clue, pointing directly to Tuberculosis.

Question ID

QiLyiawmFW5uFdklGsiF8k

Copy ID

Reference Book

E6 Pathology-Textbook of PATHOLOGYHarsh Mohan Part 1 (1-214) pp. 120-122, 121-123, 133-135