Parathyroid

Question 1

Primary hyperparathyroidism

Answer 1

Overproduction of parathyroid hormone
- Abnormal gland continues to make calcium regardless of serum calcium level

Causes:

• *1. Solitary adenoma**
• *2. Multiple gland disease**
• *3. Parathyroid cancer**

Risk factors:

• Women > men
• Post menopause (50+)

Diagnosis:

• Elevated PTH
• Hypercalcemia
• Hypercalciuria

Treatment:
- Surgical parathyroidectomy

Question 2

Solitary parathyroid adenoma

Answer 2

• Benign tumour in 1 of 4 glands
• Most common cause of primary hyperparathyroidism

Cause:

• Genetic mutation
• Inherited disorder (MEN I)

Presents:
- High serum PTH + calcium, low phosphate

Treatment:

• Reduce PTH + calcium (medical)
• Surgical resection
• *Hypoechoic solid lesion**
• Homogeneous
• Oval (~1cm)
• *Hypervascular**
• Arch
• Feeding vessel
• Differentials:*
• • Lymph node*
• • Thyroid nodule*

Question 3

Multiple gland disease

Answer 3

1. Parathyroid hyperplasia
   - Parathyroid cells divide excessively
   - Involves all 4 glands symmetrically
2. Multiple adenomas
   - Adenomas in 2-3 glands

Present:
- Hyperparathyroidism

Treatment:

• Reduce PTH + calcium (medical)
• Surgical resection
• *Asymmetrically enlarged parathyroid glands**
• Difficult to differentiate sonographically*

Question 4

Parathyroid cancer

Answer 4

• Rare
• Causes 1-2% of primary hyperparathyroidism
• Poor prognosis (invasive metastatic nature)

Presents:
- Very high serum calcium (>14mg/dL)

Treatment:
- Surgical resection

• *Heterogeneous mass**
• Internal cystic components
• Lobular contour

>2cm (lager than adenomas)

Hypervascular

Invasion of adjacent tissues

Differential = large adenoma

Question 5

Secondary hyperparathyroidism

Answer 5

Overproduction of parathyroid hormone
- Normal PT glands make excess PTH due to chronic hypocalcemia

• Often patients with chronic renal failure

Presents:

• Symptoms of CKD
• Bone demineralisation
• Calcs in soft tissues + blood vessels

Treatment:
- Treat renal failure (dialysis, transplant)

US usually not necessary