Hypercalcemia & Hyperparathyroidism

Question 1

What are the causes of hyperparathyroidism?

Answer 1

PRIMARY

• adenoma
• hyperplasia
• carcinoma

SECONDARY (conditions that lower Ca)

• chronic renal failure (renal osteodystrophy)
• malabsorption syndrome (after gastrectomy)

TERTIARY
- autonomous PTH secretion super-imposed on previous secondary hyperparathyroidism

ECTOPIC PTH

• bronchogenic carcinoma
• hypernephroma

Question 2

What is the clinical picture hypercalcemia/hyperparathyroidism?

Answer 2

NEURO MUSCULAR

• fatigue
• apathy
• psychosis
• pseudo gout
• muscular hypotonia (myopathy) -> waddling gait

EYE -> band keratopathy

CARDIOVASCULAR

• hypertension
• hypotension IF severe dehydration
• arrhythmias

SKIN -> dry, pruritus

SKELETAL

• osteomalacia
• osteoporosis
• osteitis fibrosa cystica (Von Recklinghausen disease) -> pathological fracture

GI

• anorexia, nausea, vomiting
• intestinal atony -> constipation
• peptic ulcer disease -> Zollinger Ellison syndrome
• cholelithiasis
• pancreatitis

RENAL

• nephrocalcinosis
• Ca diabetes -> excessive Ca diuresis

neck nodule

Question 3

What lab investigations are done to diagnose hyperparathyroidism?

Answer 3

1- serum calcium: normal = 8.5 - 10.5mg -> increased
2- serum phosphate: normal = 2.5 - 4mg -> decreased
3- serum alkaline phosphatase = increased in bone disease
4- plasma PTH -> increased
5- hypercalciuria

Question 4

What radiological investigations are performed for hyperparathyroidism?

Answer 4

X-RAY

• in kidneys -> stones or nephrocalcinosis
• in bones -> osteitis fibrous cystica
  - > salt & pepper appearance
  - > cod fish spine
  - > pseudo fracture (milk-man fracture) -> due to osteomalacia
• soft tissue -> calcification

Question 5

How can we localize an adenoma in hyperparathyroidism?

Answer 5

• ultrasonography & CT of the neck

- technetium thallium scanning

Question 6

What are the indications for surgery in hyperparathyroidism?

Answer 6

• adenoma -> remove

- hyperplasia -> remove 3 & a half -> implant the remaining half in the forearm

Question 7

What are the complications of surgery?

Answer 7

Hungry Bone syndrome
- rapid mineralization of decalcified bone -> tetany due tp hypocalcemia & hypomagnesemia

prevent by giving vitamin D before surgery
treatment of post-op tetany -> Ca IV + MgSo4

Question 8

What are the indications for medical treatment in hyperparathyroidism?

Answer 8

• previous unsuccessful surgery
• unfit for surgery
• refusing surgery

give -> orthophosphate salt 1-3g/day
-> estrogen in women

Question 9

How should emergency hypercalcemia be treated?

Answer 9

serum ca > 13mg 
INCREASE CA EXCRETION 
- hydration -> isotonic saline 
- frusemide 
- dialysis if renal failure occurs

Question 10

What are the causes of emergency hypercalcemia?

Answer 10

Causes

• primary hyperparathyroidism
• osteolytic carcinoma
• multiple myeloma

Question 11

What are the manifestations of emergency hypercalcemia?

Answer 11

• severe abdominal pain, vomiting, & constipation
• polyuria, dehydration, weakness
• confusion, coma

Question 12

What agents influence bone Ca fluxes?

Answer 12

• mithramycin -> inhibits bone resorption in malignant hypercalcemia
• prostaglandin inhibitors -> indomethacin
• orthophosphate -> increase phosphate level -> decreases calcium level
• corticosteroids -> give in malignancy only -> decreases bone resorption & intestinal absorption
• calcitonin -> decreases calcium release from bone & increases its excretion in urine