Sarcoidosis

Question 1

Define:

Answer 1

Multi-system granulomatous inflammatory disorder of unknown cause

Non-caseating (this is when it is a cheese like necrosis as seen in TB)

Question 2

Aetiology/risk factors:

Answer 2

UNKNOWN

Thought to be associated with : transmissable agents (viruses), environmental triggers and genetics (HLA DRB-1 and DQB1)

Question 3

Pathogenesis:

Answer 3

Unknown antigen is presented on MHC class II on macrophages to CD4+. These accumulate and release cytokines leading to granulomas.

Question 4

General Symptoms:

Answer 4

Fever 
Malaise 
Weight loss 
Bilateral parotid swelling 
Lymphadenopathy
Hepatosplenomegaly
Hypercalcaemia
Hypercalciuria 
Renal stones

Question 5

Pulmonary symptoms:

Answer 5

Breathlessness
Dry cough
Chest discomfort
Minimal clinical signs

Question 6

Muscloskletal symptoms:

Answer 6

Bone cysts – terminal phalangeal (e.g. dactylitis)
Polyarthralgia
Myopathy

Question 7

Eye symptoms:

Answer 7

Keratoconjunctivitis sicca (inflammation of the conjunctivitis and surrounding tissues due to the eyes being dry)
Glaucoma
Uveitis
Papilloedema

Question 8

Skin symptoms:

Answer 8

Lupus pernio (red-blue infiltrations of the nose, cheeks, ears and terminal phalanges)
Erythema nodosum 
Maculopapular eruptions

Question 9

Neurological symptoms:

Answer 9

Lymphocytic meningitis 
Space-occupying lesions 
Pituitary infiltration 
Cerebellar ataxia 
Cranial nerve palsies 
Peripheral neuropathy
Meningitis

Question 10

Cardiac symptoms:

Answer 10

Arrhythmia
Bundle branch block 
Pericarditis 
Cardiomyopathy
Congestive cardiac failure

Question 11

Investigations:

Answer 11

Bloods
High serum ACE in 60% (g
High calcium (due to high ACE)
High ESR 
FBC - WCC may be low due to lymphocyte sequestration in the lungs 
High Immunoglobulins 
LFTs - high ALP + GGT 

24 hr Urine Collection

Tuberculin skin test –ve in 2/3

CXR

High-Resolution CT Scan -Check for diffuse lung involvement

Gallium Scan - shows areas of inflammation

Pulmonary Function Tests – may be normal or
Low FEV1 , FVC shows restrictive picture

Bronchoscopy and Bronchoalveolar Lavage
High lymphocytes
High CD4: CD8 ratio

Transbronchial Lung Biopsy (or lymph node biopsy)
Tissue biopsy can be from lung, liver, lymph nodes, skin nodules or lacrimal glands

Question 12

What would you see on a CT at each stage:

Answer 12

Stage 0 - may be clear
Stage 1 - bilateral hilar lymphadenopathy
Stage 2 - stage 1 with peripheral pulmonary infiltration and paratracheal node enlargement
Stage 3 – peripheral pulmonary infiltration alone
Stage 4 - pulmonary infiltration and fibrosis, bulla formation (honeycombing), pleural involvement