Metabolic bone disease histopath

Question 1

Osteoporosis: aetiology (3), Disease features (3),

Answer 1

Age related
Post-menopause in women
Can be secondary to systemic disease/drugs
Features:
REDUCED BONE MASS
DEXA scan: T score > 2.5 SD below normal

Question 2

Osteoporosis Symptoms (2):

Answer 2

Low impact fractures (Hip - NOF, wrists -Colles)

Back pain

Question 3

Osteoporosis RFs (5)

Answer 3

Age
Female
smoking
Low BMI
poor diet

Question 4

Osteoporosis X ray, histology, biochemistry

Answer 4

nothing
Loss of cancellous bone
all normal - Ca, ALP, PO4

Question 5

Osteomalacia: Aetiology (4), Disease feature (1)

Answer 5

Reduced dietary vit D, malabsorption of vit D
Low sunlight
genetic
Disease feature: REDUCED BONE MINERALIZATION

Question 6

Osteomalacia: symptoms - adults (2), children (4)

Answer 6

adults - bone pain, proximal muscle weakness

children - bone pain, bowing of tibia, rachitic rosary, delayed walking

Question 7

Osteomalacia: RFs (4)

Answer 7

Poor diet
Malabsorption
CKD
Lack of sunlight

Question 8

Osteomalacia: X-ray

Answer 8

LOOSER’S ZONES (pseudo fractures) - splaying of metaphysis

Question 9

Osteomalacia: histology (1) & biochem

Answer 9

Excess UNMINERALIZED bone (osteoid)
biochem - low or norm Ca
Low PO4
raised ALP

Question 10

Primary hyperparathyroidism: Aetiology (5) & Disease features (1)

Answer 10

Excess PTH - increased Ca2+ reabsorption & PO4- excretion
causes - Parathyroid adenoma, hyperplasia, carcinoma, MEN
Feature - bone changes of osteitis fibrosa cystica

Question 11

Primary hyperparathyroidism: symptoms

Answer 11

Hypercalcaemia - moans, bones, stones, groans, psychiatric overtones
depression, renal stones, bone pain, constipation, pancreatitis, polyuria, polydipsia

Question 12

Primary hyperparathyroidism: RFs

Answer 12

Secondrary hyperPTH > CRF
low vit D
malabsorption

Question 13

Primary hyperparathyroidism: X-ray findings (3)

Answer 13

BROWN’S TUMOUR
SALT AND PEPPER SKULL
subperiosteal BONE RESORPTION in PHALANGES

Question 14

Primary hyperparathyroidism: histology (1) & biochem

Answer 14

Histo - osteitis fibrosa cystica (marrow fibrosis + cysts - AKA Brown tumour)
Biochem - raised Ca, low/ norm PO4, high/norm ALP

Question 15

Paget’s disease: aetiology, disease features

Answer 15

A disorder of bone turnover

Both lytic & sclerotic lesions

Question 16

Paget’s disease: symptoms (6)

Answer 16

bone pain
microfractures
high output CF
nerve compression
skull changes - increase head size
deafness

Question 17

Paget’s disease: RFs (2)

Answer 17

> 50 yrs

Caucasian

Question 18

Paget’s disease: X-ray findings in skul (2), vertebrae (2), pelvis (2)

Answer 18

Skull - osteoporosis circumscripta, cotton wool
vertebrae - picture frame, ivory vertebrae
Pelvis – sclerosis & lucency

Question 19

Paget’s disease: histology (2)

Answer 19

HUGE OSTEOCLASTS - with > 100 nuclei

MOSAIC PATTERN - of lamellar bone

Question 20

Paget’s disease: biochem

Answer 20

Main thing is very ELEVATED ALP

Ca & PO4 normal

Question 21

Renal osteodystrophy - aetiology

Answer 21

All skeletal changes assocaited with CKD:
osteitis fibrosia cystica (secondary to raised PTH)
osteomalacia
osteoporosis
osteosclerosis

Question 22

Renal osteodystrophy - biochem:

Answer 22

Low Ca
Raised PO4
secondary hyperPTH & metabolic acidosis