Histopathology - Sarcoidosis

Question 1

What is sarcoidosis?

Answer 1

• A multisystem disease of unknown cause
• Commonly affects young adults
• Characterised by non-caseating glanulomas in many tissues

Question 2

What are the histological features of Sarcoidosis?

Answer 2

• Non-caseating granulomas
• Schaumann bodies (inclusions of protein + calcium)
• Asteroid bodies (inclusions of protein)

Question 3

What are some general features of sarcoidosis?

Answer 3

• More severe disease in Afro-Caribbeans
• F>M
• 40-60yrs
• Lungs most commonly involved
• Often detected at routin CXR (bilateral hilar lymphadenopathy) + pulmonary infiltrates (fine nodular shadowing in mid-zones)
• Most seek help with insidious SOB, Cough, Chest Pain + Night Sweats

Question 4

What are the extrapulmonary manifestations of Sarcoidosis?

Answer 4

Skin:
- Erythema nodosum
- Lupus pernio (red/purple lesions around nose)
- Skin nodules

LNs:
- Lymphadenopathy
- Painless + rubbery

Joints:
- Arthritis
- Bone cysts

Eyes:
- ANTERIOR UVEITIS (misting of vision + painful red eye)
- POSTERIOR UVEITIS (progressive visual loss)
- UVEOPAROTID FEVER (bilateral uveitis, parotid enlargement +/- facial nerve palsy)
- KERATOCONJUNCTIVITIS
- LACRIMAL GLAND ENLARGEMENT

Liver/Spleen:
- Hepatosplenomegaly

Blood:
- Leukopenia
- Anaemia

Hypercalcaemia/hypercalciuria:
- Renal calculi
- Nephrocalcinosis

Heart:
- Dysrhythmias
- Cardiomyopathy
- Conduction defects
- Pericarditis

CNS involvement

Constitutional Sx:
- Malaise
- Fever
- Weight loss
- Night sweats

Question 5

How is sarcoidosis diagnosed?

Answer 5

Diagnosis of exclusion

Question 6

What are the investigative findings of sarcoidosis?

Answer 6

• Raised Ca2+ (ectopic 1-α hydroxylase release by activated macrophages)
• Raised ESR
• Raised ACE
• Transbronchial biopsy = non-caseating granuloma
• Spirometry = restrictive