Histopathology

Question 1

Which of the following is not a risk factor for atherosclerosis?

1. Type 2 Diabetes Mellitus
2. Hypertension
3. Hypercholesterolaemia
4. Female gender
5. Smoking

Answer 1

A 4. Male gender is a risk factor

Question 2

Which of the following is not a feature of hypertrophic cardiomyopathy?

1. Thick walled, heavy and hyper contracting heart
2. Mutations in the beta-MHC gene most common
3. Myocyte disarray is seen histologically
4. 15-20% go on to develop dilated cardiomyopathy
5. Can be caused by alcohol, sarcoidosis and myocarditis

Answer 2

A5. This is true of dilated cardiomyopathy

Question 3

Which of the following is not a feature of Acute Rheumatic Fever?

1. Develops 2-4 weeks after a strep throat infection
2. Metronidazole therapy
3. Aschoff bodies and anitschov myocytes
4. Erythema marginatum
5. Subcutaneous nodules

Answer 3

A3. Treatment is with benzylpenicillin or erythromycin if allergic. Remember Jones’ major criteria (CASES)

Carditis

Arthritis

Sydenham’s chorea

Erythema marginatum

Subcutaneous nodules

Histology: beady, fibrous vegetations, Aschoff bodies (small giant cell granulomas) and anitschov myocytes (regenerating myocytes)

Question 4

This description is characteristic of which form of vegetative endocarditis? “Large, irregular masses on valve cusps, extending into the chordae”

1. Rheumatic heart disease
2. Infective endocarditis
3. Non-bacterial thrombotic endocarditis
4. Libman-Sacks endocarditis
5. Viral endocarditis

Answer 4

A2. This describes infective endocarditis, which is due to colonisation of heart valves or mural endocardium by microbes.

1. Rheumatic - small, warty vegetations caused by antigenic mimicry.
2. Non-bacterial thrombotic - small, bland vegetations formed of thrombi. Caused by DIC/hypercoagulable states.
3. Libman-Sacks - small, warty, stable, platelet rich. Associated with SLE.

Question 5

Which of the following is not one of the HACEK microorganisms?

1. Haemophilus
2. Aggregatibacter
3. Coxiella
4. Eikenella
5. Kingella

Answer 5

A3. Cardiobacterium is the “C” in HACEK, a group of organisms that cause culture-negative infective endocarditis. Typical organisms of acute IE include S aureus and Strep pyogenes. Typical causes of subacute IE include Strep viridans and staph epidermis.

Question 6

Which of the following is not one of the Duke criteria for diagnosing Infective Endocarditis?

1. Positive culture of typical organism
2. Evidence of vegetation or abscess on echo or new regurgitant murmur
3. Risk factor e.g. prosthesis, IVDU
4. Prolonged PR interval
5. Fever >38

Answer 6

4. Prolonged PR is one of the Jones’ minor criteria for acute rheumatic fever. Other Duke minor criteria include thromboembolic phenomena e.g. Janeway lesions or splinter haemorrhages, and immune phenomena e.g. Roth spots and Osler’s nodes.

Question 7

Which of the following is not a cause of pericarditis?

1. MI
2. Uraemia
3. Metabolic alkalosis
4. Staphylococcus
5. TB

Answer 7

A3. Types (causes) of pericarditis:

• Fibrinous (MI, uraemia)
• Purulent (Staphylococcus)
• Granulomatous (TB)
• Haemorrhagic (tumour, TB, uraemia)
• Fibrous/Constrictive (any of above)

Question 8

Which organism is associated with Humidifier’s lung?

1. Saccharopolyspora rectivirgula
2. Thermactinomyces spp.
3. Aspergillus clavatus
4. Aspergillus fumigatus
5. Penicillium casei

Answer 8

A2.

1. Associated with Farmer’s lung due to mouldy hay
2. Malt-workers and Cheese washer’s lung
3. Malt-workers lung
4. Cheese washer’s

Question 9

Which autosomal dominant condition involves increased risk of parathyroid tumours, phaeochromocytoma and medullary thyroid tumours?

Answer 9

A. MEN 2a

MEN 1 (3Ps): Pituitary, Pancreatic, Parathyroid

MEN2a (2Ps, 1M): Parathyroid, Phaeo, Medullary thyroid

MEN2b (1P, 2Ms): Phaeo, Medullary thyroid, Mucocutaneous neuromas (and Marfanoid phenotype).

Question 10

Which of the following metabolic bone disorders shows marrow fibrosis and cysts on histology?

1. Osteoporosis
2. Osteomalacia
3. Hyperparathyroidism
4. Paget’s
5. Rickets

Answer 10

A3. Hyperparathyroidism may show osteitis fibrosa cystica (marrow fibrosis + cysts - aka Brown Tumour)

1. Osteoporosis - loss of cancellous bone
2. Osteomalacia - excess unmineralised bone
3. Paget’s - huge osteoclasts, mosaic pattern
4. Rickets - like osteomalacia

Note - Renal osteodystrophy may show any of the above

Question 11

A 56 year old woman is investigated for decompensated liver disease. A biopsy shows a golden-brown deposition in the liver parenchyma that stains blue with Perl’s Prussian blue.

1. Cirrhosis
2. Haemosiderosis
3. Wilson’s disease
4. Haemochromatosis
5. Non-alcoholic steatohepatitis

Answer 11

A. Haemochromatosis

An AR mutation in HFE leading to haemosiderin deposition in the liver (cirrhosis) pancreas (diabetes), skin (bronzing), heart (cardiomyopathy) and gonads (atrophy and impotence). Progresses to inflammation and subseqeunt fibrosis.

Note: haemosiderosis is defined as excess haemosiderin deposition due to an acquired cause (alcohol and blood transfusion). No architectural change (cirrhosis) unless severe.

Question 12

A 40 year old diabetic man arrives to the walk-in clinic with a number of annular lesions and petechiae the day after his outpatients appointment . Upon gently rubbing his skin there is no sloughing.

1. Toxic Epidermal Necrolysis (TEN)
2. Erythema marginatum
3. Stevens Johnson Syndrome (SJS)
4. Erythema multiforme
5. Erythema nodosum

Answer 12

A. 4 Erythema multiforme (pictured below)

Few to hundreds of target lesions (+/- macules, papules, urticarial wheals, vesicles, bullae, and petechiae) appear within 24 hours of infection with mycoplasma and HSV or administraiton of sulphonamides (gliclazide in this case), NSAIDs, allopurinol, penicillin or phenyotin (SNAPP).

1, 3. SJS/TEN must be excluded in this case as it has 30% mortality. It typically presents after 2-3 days of fever +/- sore eyes, throat and itch. Mucous membrane involvement precedes skin. Nikolsky sign is positive. (SJS affects <10% body SA, TEN >30%)

2. Erythema marginatum is an annular erythema, but occurs in acute rheumatic fever (CASES). Unlike multiforme it almost never occurs on the face, palms or soles.
3. Erythema nodosum is associated with recent infection or in response to sulphonamides, among other drugs, but appears as red lumps/nodules on the shins, knees and/or ankles.

Question 13

A 23 year old woman presents to her GP with pain and stiffness in her hands and a salmon pink rash on her arms. The GP - aware of the importance of pathology in medical practice - pulls out his trusty microscope and some H&E from under his desk. On staining, samples of the rash show parakeratosis and clubbing of rete ridges.

1. Eczema
2. Lichen Planus
3. Systemic Juvenile Idiopathic Arthritis
4. Psoriasis
5. Adult-onset Still disease

Answer 13

A4. Psoriasis (histology pictured)

Commonest is chronic plaque psoriasis with salmor pink plaques with silver scale affecting extensor aspects. Associated with nail changes and arthritis.

Buzzwords: Auspitz’ sign (rubbing causes pinpoint bleeding), Koebner phenomenon (lesions form at sites of trauma).

Histology: paraketosis, clubbing of rete ridges (“test tubes in a rack”) and Munro’s microabscesses

Question 14

Lesions are pruritic, purple, polygonal, papules and plaques with a mother of pearl sheen and fine white network on their surface called Wickam’s striae.

Usually on inner surface of wrists.

Answer 14

A. Lichen Planus

Histology: hyperkeratosis with saw-toothing of rete ridges

Question 15

A 60 year old man with a history of colon cancer and TIA suffers a stroke. On examination, heart sounds are normal but an echocardiogram shows small, bland vegetations on the aortic valve attached to lines of closure.

1. Rheumatic heart disease
2. Non-bacterial thrombotic endocarditis
3. Infective endocarditis
4. Libman-Sacks endocarditis
5. HACEK endocarditis

Answer 15

A2. Non-bacterial thrombotic endocarditis

Affects patients >40yo and charecterised by absence of inflammation or bacteria. More commonly affecting left-sided valves and associated with malignancy. Source of emboli.

1. Rheumatic heart disease - small, warty vegetations along line of closure, associated with Rheumatic Fever
2. IE - Large, irregular masses on valve cusps
3. Libman-Sacks - small, warty vegetations that are sterile and plt rich, associated with SLE and APLS
4. HACEK - atypical bacteria causing culture negative infective endocarditis

Question 16

A 60 year old man dies from an acute myocardial infarction while doing his morning exercises. A post-mortem examination of the heart muscle shows loss of nuclei, homogenous cytoplasm and necrotic cell death. There is no infiltration of polymorphs or macrophages. How long after the event did he die?

1. Under 6 hours
2. That evening
3. Days after the attack
4. Within the first two weeks
5. Many weeks later

Answer 16

A2. That evening

Evolution of MI - histological findings:

• <6 hrs - normal histology and CK-MB
• 6-24hrs - loss of nuclei, homogenous cytoplasm
• 1-4 days - inflitration of polymorphs and macrophages to clear up debris
• 5-10 days - removal of debris
• 1-2 weeks - granulation tissue, angiogenesis, myofribroblasts, collagen synthesis
• Later - strengthening, decellularising scar tissue

Question 17

On post mortem of a man with resting tremor and cogwheel rigidity, histological examination shows alpha-syncuclein but no Lewy bodies.

1. Idiopathic Parkinson’s disease
2. Multiple system atrophy
3. Pick’s disease
4. Alzheimer’s disease
5. Familial Parkinson’s

Answer 17

A5. Familial Parkinson’s

Mutation in alpha-synuclein leads to no Lewy bodies. Worse prognosis with earlier onset and no response to levodopa.

1. Idiopathic Parkinson’s - Lewy bodies in dopaminergic neurons of substantia nigra leading to tremor, rigidity, akinesia and postural instability
2. MSA - alpha synuclein and Papp-Lantos inclusions. Parkinson’s + autonomic dysfunction. Poor response to L-DOPA
3. Pick’s - Tau proteins, behavioural change, aphasia, hostile to family
4. Alzheimer’s - tau, beta-amyloid, Mx donepezil, memantine

Question 18

The activity of plaques in a 24 year old woman with multiple sclerosis is described with the presence of oedema, macrophages and some myelin breakdown.

1. Acute plaque
2. Early chronic active plaque
3. Late chronic active plaque
4. Chronic inactive plaque
5. Shadow plaque

Answer 18

A2. Early chronic active plaque

1. Acute plaque - minor changes e.g. oedema, difficult to recognise
2. Early chronic active - oedema, macrophages, some myelin loss
3. Late chronic active - complete loss of myelin, macrophages contain debris, mild perivascular inflammation
4. Chronic inactive - complete loss of myelin, no macrophages
5. Shadow - nearly complete remyelination (thin), scattered macrophages

Question 19

A 66 year old with a 40 pack year history presents to her GP with gradually worsening dyspnoea and cough productive of sputum on most days. On examination, she is cyanosed, tachypnoeic and wheezing. What’s the cause of his

1. Pulmonary embolus
2. Bronchiectasis
3. Emphysema
4. Chronic bronchitis
5. Pneumonia

Answer 19

Obstructive lung disease is characterised by airway obstruction and a decreased FEV1/FVC ratio. COPD includes chronic bronchitis and emphysema and is associated with smoking.

Chronic bronchitis is due to dilated airways, goblet cell hyperplasia and mucous gland hypertrophy –> productive cough, wheeze, hypoxia and recurrent infection.

Emphysema is due to alveolar destruction –> dyspnoea +/- cough, cyanosis in end stage. Occurs without bronchitis in a1-AT deficiency.

Question 20

Which non-neoplastic bone tumour has a ‘soap bubble’ appearance on XR and a Shepherd’s crook deformity?

Answer 20

A. Fibrous dysplasia (benign)

More common in women and femurs. Biopsy shows “chinese letters” irregular trabeculae.

Question 21

Polyostotic dysplasia + cafe au lait spots + precocious puberty

Answer 21

A. Albright syndrome

Question 22

46 year old man presents with severe pain in his finger following swelling. XR shows cotton wool calcification and a lytic lesion.

Answer 22

A. Enchondroma (benign)

Occurs in middle age and hands.

Ollier’s syndrome = multiple enchondromas

Maffuci’s syndrome = multiple enchondromas + haemangiomas

Question 23

A 13 year old boy is brought to the GP by his mother who is concerned that he is not tall enough. On examination he has a well defined bony protruberance on his proximal left femur, near the hip.

Answer 23

A. Osteochondroma (benign)

Occurs in teenagers and long bones. May present with pain after exercise.

Question 24

A 12 year old girl presents with unilateral pain in her shin that is dull, occurs at night and is relieved by aspirin. A UCL- trained doctor turns her away with growing pains. She has an X-ray done privately which shows a radiolucent nidus with a sclerotic rim.

Answer 24

A. Osteoid osteoma

Small benign bone lesion. Occurs in adolescents and tibia/femur.

Speckled mineralisation = osteoblastoma
(Because having spectacles is a blast! #killmenow)

NB// Growing pains commonly occur age 3-12, are bilateral and muscular rather than joint/bone. They also occur mostly at night.

Question 25

Severe shortness of breath and tachypnoea 24-48 hours post trauma, burns or sepsis

Answer 25

A. Acute respiratory distress syndrome (ARDS)

Characterised by inflammation in the lung parenchyma impairing gas exchange.

Question 26

A man presents to A&E having fallen off his bike. XR shows a fracture in the midshaft of his left humerus that appears splintered although the soft tissue is intact.

Answer 26

A. Comminuted/segmental fracture

Question 27

Joint aspirate shows negatively birefringent crysals under polarized red light

Answer 27

A. Gout

Needle shaped monosodium urate cystals +/- tophi under skin.

Pseudogout = calcium pyrophosphate crystals are rhomboid and positively birerefringent

Question 28

A 30 year old man presents with nosebleeds, oliguria and a rash on his legs. His eGFR is reduced and urinalysis finds casts containing both white and red blood cells. He overhears the nephrologist explain to the student that he is likely to need dialysis within weeks.

Answer 28

A. Pauci-immune crescent glomerulonephritis

Associated with ANCA (c- and p- i.e. GPA and MPA) and strongly associated with rapidly progressive (cresenteric) glomerulonephritis.

Light microscopy: crescents

Fluorescence: lack of immune complex deposition

Question 29

Most common cause of purulent meningitis in children over 6 years old

Answer 29

A. S. pneumoniae

Neonates - GBS, E. coli

Older children/adolescent - N. meningitidis (rash)

Question 30

A 60 year old known alcoholic with a pancreatic mass complains of abdominal discomfort and dificulty digesting food following acute pancreatitis

Answer 30

A. Pseudocyst

Complication of acute pancreatitis or in children, trauma. The cyst is a collection of fluid and necrotic inflammatory debris. Common issues are mild abdnominal pain and digestion issues. Reolve spontaneously.

Question 31

What is the best indicator for portal hypertension?

1. Splenomegaly
2. Hepatomegaly
3. Spider naevi
4. Jaundice
5. Liver flap

Answer 31

A. Splenomegaly

Portal HTN is most commonly caused by cirrhosis. Most of the signs described are signs of cirrhosis and not specific to portal HTN, in which the spleen enlarges due to increased retrograde pressure. Other signs: caput medusae, peripheral oedema and gynaecomastia (RARE)

Question 32

A 60 year old man presents with a fracture in the midshaft of the femur. He is otherwise well apart from some difficulties going to urinate.

Answer 32

A. Adenocarcinoma

A pathological fracture combined with urinary symptoms points towards a secondary bone cancer from a prostate primary. While primary bone cancer can cause pathological fractures, they are rarer and do not often occur in the mid-shaft of the femur.