Hyperparathyroidism Flashcards
Parathyroid Disorder
Define Hyperparathyroidism
Involves overactivity of the parathyroid glands with high levels of parathyroid hormone (PTH)
What are the three types of hyperparathyroidism?
Primary, secondary, and tertiary hyperparathyroidism
What causes primary hyperparathyroidism?
Uncontrolled PTH secretion due to a parathyroid tumour
What causes secondary hyperparathyroidism?
Vitamin D deficiency or chronic renal failure leading to compensatory PTH increase
What causes tertiary hyperparathyroidism?
Long-term secondary hyperparathyroidism leading to parathyroid hyperplasia and autonomous PTH secretion
What is the key effect of primary hyperparathyroidism?
Increased PTH leads to hypercalcaemia
What symptoms result from hypercalcaemia in primary hyperparathyroidism?
(1) Fatigue
(2) Depression
(3) Bone pain
(4) Myalgia
(5) Nausea
(6) Thirst
(7) Polyuria
(8) Renal stones
(9) Osteoporosis
Why does secondary hyperparathyroidism cause hypocalcaemia?
Increased PTH occurs in response to low calcium due to poor intestinal, renal, and bone absorption
What happens in tertiary hyperparathyroidism?
Chronic overstimulation leads to gland hyperplasia and excessive PTH, causing hypercalcaemia
What are the main functions of PTH?
(1) Activates osteoclasts → bone resorption → releases calcium
(2) Increases renal calcium reabsorption
(3) Increases urinary phosphate excretion
(4) Stimulates vitamin D synthesis → enhances calcium absorption
What normally stops PTH secretion?
Increased serum calcium provides negative feedback
What additional blood abnormality is seen in primary hyperparathyroidism?
Hypophosphataemia (low phosphate levels)
Which bones are most affected by osteoporosis in hyperparathyroidism?
Phalanges, vertebrae, and femur
What are the blood findings in primary hyperparathyroidism?
High PTH
High calcium
Low phosphate
What are the blood findings in secondary hyperparathyroidism?
High PTH
Low/normal calcium
Low phosphate in Vitamin D deficiency
High Phosphate in Chronic Kidney Disease
What are the blood findings in tertiary hyperparathyroidism?
Very high PTH
High calcium
High phosphate
How is primary hyperparathyroidism treated?
Surgical removal of the parathyroid tumour
cinacalcet
How is secondary hyperparathyroidism managed?
Correcting vitamin D deficiency or performing a renal transplant
cinacalcet
How is tertiary hyperparathyroidism treated?
Surgical removal of part of the parathyroid tissue.
Managed with medication like Cinacalcet
A 52-year-old woman presents to her GP with a history of constipation and generalised fatigue. She was recently hospitalised due to renal colic, and imaging revealed calcium oxalate renal stones. She denies any recent dietary changes and has no history of gastrointestinal disorders. Laboratory tests show hypercalcemia and a raised parathyroid hormone (PTH) level.
Given the likely diagnosis, what is the most appropriate underlying cause?
Primary
= Parathyroid gland adenoma
A 45-year-old asian woman presents to her GP with fatigue and pain in her lower back and hips. Her GP sends a series of blood tests to investigate her symptoms, which reveal that she is severely vitamin D deficient.
What values might you expect from her remaining blood tests?
Low calcium
low phosphate
high parathyroid hormone
high ALP
A 74-year-old male presents to his GP with a history of vomiting and constipation. He has no significant medical history of note.
The GP requests tests of parathyroid function which show the following results:
(1) Calcium 3.43 mmol/L (2.1 – 2.6 mmol/L)
(2) Parathyroid hormone 7.4 pmol/L (1.6 - 6.9 pmol/L)
What is the most likely diagnosis?
Primary hyperparathyroidism
A 72-year-old woman has been feeling unwell for several years with the clinical manifestations of primary hyperparathyroidism including renal stones, osteopenia and low mood.
She has neck imaging which confirms a solitary parathyroid adenoma and she is listed for a parathyroidectomy.
What is the commonest complication of this procedure?
Hypocalcaemia
What is a common complication of primary hyperparathyroidism?
Kidney stones
An 83-year-old woman presents with polyuria, polydipsia, constipation and depression. Her serum calcium, parathyroid hormone, and alkaline phosphatase (ALP) are raised, and you suspect a diagnosis of primary hyperparathyroidism.
How does parathyroid hormone act on the bone to increase serum calcium levels?
Binds to osteoblasts, which stimulate osteoclasts via paracrine signalling
A 35-year-old lady is under the care of the neurosurgeons for treatment of a pituitary adenoma. Following endocrine testing, this is found to be non-functional. However, before surgery she is found to have a high serum calcium level of 3.8 nmol/l (normal range 2.2-2.6 nmol/l). A diagnosis of hyperparathyroidism is then made.
It is suspected that she may have an endocrine syndrome affecting multiple parts of her body.
What investigation should you undertake next?
CT Pancreas
Primary hyperparathyroidism is most commonly due to what?
Solitary parathyroid adenoma
