Parathyroid glands and disorders of calcium metabolism

Question 1

PTH (Elevated)
Ca2+ (Elevated)
Phosphate (Low)
Urine calcium : creatinine clearance ratio > 0.01

Answer 1

Primary Hyperparathyroidism

Question 2

Symptoms of Primary Hyperparathyroidism

Answer 2

May be asymptomatic if mild
Recurrent abdominal pain (pancreatitis, renal colic)
Changes to emotional or cognitive state

Question 3

Cause of Primary Hyperparathyroidism

Answer 3

solitary adenoma (80%)
multifocal disease in 10-15%
parathyroid carcinoma in ~1%

Question 4

PTH (Elevated)
Ca2+ (Low or normal)
Phosphate (Elevated)
Vitamin D levels (Low)

Answer 4

Secondary Hyperparathyroidism

Question 5

Symptoms of Secondary Hyperparathyroidism

Answer 5

May have few symptoms
Eventually may develop:
- bone disease
- osteitis fibrosa cystica
- soft tissue calcifications

Question 6

Cause of Secondary Hyperparathyroidism

Answer 6

Parathyroid gland hyperplasia due to low calcium
(almost always in a setting of chronic renal failure)

Question 7

Ca2+ (Normal or high)
PTH (Elevated)
Phosphate levels (Decreased or Normal)
Vitamin D (Normal or decreased)
Alkaline phosphatase (Elevated)

Answer 7

Tertiary hyperparathyroidism

Question 8

Symptoms of Tertiary Hyperparathyroidism

Answer 8

Metastatic calcification
Bone pain and / or fracture
Nephrolithiasis
Pancreatitis

Question 9

Cause of Tertiary Hyperparathyroidism

Answer 9

ongoing hyperplasia of the parathyroid glands
after correction of underlying renal disorder
=> hyperplasia of all 4 glands is usually the cause

Question 10

Indications for surgery in Primary Hyperparathyroidism

Answer 10

Elevated serum Calcium > 1mg/dL above normal
Hypercalciuria > 400mg/day
Creatinine clearance < 30% compared with normal
Episode of life threatening hypercalcaemia
Nephrolithiasis
Age < 50 years
Neuromuscular symptoms
Reduction in bone mineral density of the femoral neck, lumbar spine, or distal radius

Question 11

indications for surgery in Secondary (Renal) Hyperparathyroidism

Answer 11

**NOTE usually medically managed

Bone pain
Persistent pruritus
Soft tissue calcifications