Granuloma
Characterised by caseating or necrotising granulomas in affected organs
What our notes say
- Characterised by caseating or necrotising granulomas in affected organs (Internal Medicine Respiratory CAT 1: 30 MCQs and 5 short answer questions)
- A transbronchial biopsy is performed that microscopically shows numerous small pulmonary interstitial non-caseating granulomas. (Respiratory system pathology mcqs — Past Paper Questions & Answers)
- Which of these is the commonest cause of infectious granulomas (Pathology Continuous Assessment July 2021)
- Granulomas are characterised by all of the following EXCEPT (General Pathology)
- In granulomas, epithelioid and giant cells are derived from (General Pathology)
- Granulomas are characterised by all of the following EXCEPT: (Medical MCQs: Chemical Pathology & Haematology Exam Review)
Study material on Granuloma
- Lung Pathology — Must-Know
- Respiratory System Pathology 1A
- Medical MCQs: Chemical Pathology & Haematology Exam Review
- Respiratory Pathology 1b
- Respiratory system pathology mcqs
- End Sem Cat: Respiratory Pathology: Emphysema, ARDS, Pneumoconiosis
- Medical Microbiology III Exam: Viruses, Fungi & Diagnosis
- VASCULAR PATHOLOGY — Must-Know Comprehensive Notes
- Mbmm3311 – Medical Bacteriology
- General Pathology
- Inflammation and Tissue Repair - MCQs
- General Pathology
- General Pathology Continuous Assessment July 2021
Practice questions on Granuloma
A patient with tuberculosis shows granulomas with central necrosis on biopsy. What type of necrosis characterizes tuberculous granulomas?
- Coagulative necrosis
- Liquefactive necrosis
- Caseous necrosis
- Fat necrosis
- Gangrenous necrosis
Answer: C. Tuberculous granulomas specifically show caseous necrosis - grossly it has a cheese-like appearance, and microscopically it appears as amorphous, structureless, eosinophilic granular debris with complete loss of cellular details. This is distinct from coagulative necrosis (where cell outlines are preserved, seen in infarcts) and liquefactive necrosis (complete digestion of cells, seen in brain infarcts and abscesses)
In examining a lung biopsy from a patient with sarcoidosis, noncaseating granulomas are seen. What distinguishes noncaseating from caseating granulomas?
- Noncaseating granulomas lack epithelioid macrophages
- Noncaseating granulomas have absent central necrosis
- Noncaseating granulomas contain more neutrophils
- Noncaseating granulomas lack giant cells
- Noncaseating granulomas indicate bacterial rather than immune etiology
Answer: B. Caseating vs noncaseating refers to the presence/absence of central necrosis. Caseating granulomas (TB, some fungi) have central caseous necrosis surrounded by epithelioid macrophages and Langhans giant cells. Noncaseating granulomas (sarcoidosis, Crohn disease, foreign body reactions) have collections of epithelioid macrophages and often giant cells BUT lack the central necrotic zone. BOTH types contain epithelioid
A patient with Crohn disease shows intestinal biopsy with noncaseating granulomas and dense chronic inflammatory infiltrate. What is the proposed pathogenesis?
- Persistent mycobacterial infection resistant to clearance
- Immune reaction against intestinal bacteria or self antigens
- Foreign body reaction to dietary components
- Deficient innate immunity allowing bacterial overgrowth
- Excessive Th2 response to helminthic parasites
Answer: B. Crohn disease is an inflammatory bowel disease thought to result from inappropriate, unregulated immune responses against normal intestinal bacteria (commensal flora) and possibly self antigens in genetically susceptible individuals. This is an immune-mediated granulomatous inflammation. While early theories suggested persistent mycobacterial infection (Mycobacterium avium subspecies paratuberculosis), this has not b
A 50-year-old Swedish non-smoking seamstress has dyspnea, fever, hilar lymphadenopathy, reticulonodular infiltrates, anergy on skin testing, and non-caseating interstitial granulomas on biopsy. Most likely diagnosis?
- Berylliosis
- Histoplasmosis
- Sarcoidosis
- Tuberculosis
Answer: C. Non-caseating granulomas + hilar lymphadenopathy + anergy = sarcoidosis. Corticosteroids are the treatment but infection must be excluded first. ---
A young man uses intravenous drugs and develops pulmonary hypertension. Lung biopsy shows granulomas with birefringent crystals under polarized light. The likely substance is
- Silica particles from contaminated needles
- Asbestos fibers from environmental exposure
- Magnesium trisilicate (talc) from IV drug mixture
- Coal dust from occupational inhalation
Answer: C. IV drug abuse introduces magnesium trisilicate (talc) as a filler in drug mixtures into the pulmonary microvasculature. Talc elicits a granulomatous response; vascular involvement leads to pulmonary hypertension. Talc crystals are visible by polarized light. ---
A patient has fever, weight loss, and granulomas with acid-fast bacilli in liver and bone marrow. Chest X-ray is normal. Most likely organism:
- Mycobacterium tuberculosis
- Mycobacterium avium complex (MAC)
- Actinomyces israelii
- Nocardia asteroides
Answer: B. Disseminated infection with Mycobacterium avium complex (MAC) is common in individuals with advanced HIV/AIDS. It can present with fever, weight loss, lymphadenopathy, and involvement of organs like the liver and bone marrow, often with acid-fast bacilli seen on microscopy. Pulmonary involvement may be absent initially.