1. The parathyroid glands develop from the third and fourth branchial pouches during embryology. There are typically four parathyroid glands in adults, with the superior glands usually located near the thyroid and the inferior glands located lower in the neck. 2. Parathyroid disorders include hypoparathyroidism caused by low calcium levels and hyperparathyroidism caused by excessive PTH levels. Primary hyperparathyroidism is usually due to a benign adenoma and presents with increased calcium levels. 3. Symptoms of hyperparathyroidism range from being asymptomatic to musculoskeletal and renal problems. Diagnosis involves blood tests showing elevated calcium and PTH levels. Treatment is surgical

1. Parathyroid disorders

2. Embryology and anatomy
• The superior parathyroid glands are derived from the
fourth branchial pouch and the inferior glands from the
third branchial pouches.
• The position of normal superior parathyroid glands is more
consistent, with 80% of these glands being found near the
posterior aspect of the upper and middle thyroid lobes, at
the level of the cricoid cartilage
• The most common location for inferior glands is within a
distance of 1 cm from a point centered where the inferior
thyroid artery and RLN cross.
• Approximately 15% of inferior glands are found in the
thymus
• The frequency of intrathyroidal glands is about 2%.

5. • Most individuals have four parathyroid glands.
• The superior glands usually are dorsal to the RLN at the
level of the cricoid cartilage, whereas the inferior
parathyroid glands are located ventral to the nerve.
• Appear golden yellow to light brown in adults.
• Parathyroid color depends on cellularity, fat content,
and vascularity.
• Normal parathyroid glands are located in loose tissue
or fat and are ovoid.
• They measure up to 7 mm in size

7. • Arterial supply is mainly by branches from the
inferior thyroid artery, although branches from
the superior thyroid artery supply at least 20% of
upper glands.
• Venous drainage is by ipsilateral superior, middle,
and inferior thyroid veins.
• Histologically, parathyroid glands are composed
of chief cells, oxyphil cells and water-clear cells –
all the three cell types have ability to secret PTH.

8. PHYSIOLOGY
• Calcium is the most abundant cation in human
beings, and has several crucial functions.
• Extracellular calcium levels are 10,000-fold higher
than intracellular levels, and both are tightly
controlled.
• Extracellular calcium is important for excitation-
contraction coupling in muscle tissues, synaptic
transmission in the nervous system, coagulation,
and secretion of other hormones.
• Intracellular calcium is an important second
messenger regulating cell division, motility,
membrane trafficking, and secretion

9. • Hypoparathyroidism
– Parathyroid tetany is due to hypocalcaemia
– Etiology
• Thyroidectomy
• Parathyroid surgery
• Maternal hypoparathyroidism -Newborn born to
mother with undiagnosed hypoparathyroidism .
– Symptoms appear in the first few days of life
• Autoimmune disease

10. – Presentation
• The first symptoms are tingling and numbness in the face, fingers and
toes
• Cramps in the hands a - carpopedal spasm
• Stridor
• Latent tetany may be demonstrated by
– Chvostek’s sign
– Trousseau’s sign
– Diagnosis
• History
• Low serum Ca++ level
– Treatment
• Calcium gluconate
• Vitamin D
• Magnesium supplements

11. • Hyperparathyroidism
– Primary HPT is the third most common endocrine
disorder, after diabetes mellitus and thyroid
disease
– Middle-aged and elderly women are most
commonly affected by the disease
– Hyperparathyroidism is associated with an
increased secretion of parathyroid hormone

12. • Classification
1. Primary hyperparathyroidism
– There are elevated serum calcium and intact PTH
(iPTH) levels
– normal or increased urinary calcium
– normal renal function
– is due to parathyroid adenoma or hyperplasia, and
very rarely carcinoma.
– Ionizing radiation and familial predisposition
– Lithium therapy
***In benign familial hypocalciuric hypercalcemia
urinary calcium is low – a hereditary disease that
cannot be corrected by parathyroidectomy

13. 2. Secondary hyperparathyroidism
– is seen in the setting of chronic renal failure
– In renal failure there is chronic hypocalcemia, which
stimulates PTH secretion and parathyroid hyperplasia
– Other less common causes of secondary HPT include
malabsorption syndromes
– All four glands are affected by hyperplasia
3. Tertiary hyperparathyroidism
– in tertiary HPT there is autonomous hyperfunction
and the parathyroids no longer respond to calcium
feedback inhibition, which results in hypercalcemia.

14. • Acute hyperparathyroidism
– Presents as nausea and abdominal pain followed by
severe vomiting, dehydration, oliguria and finally
coma.
– The serum calcium is very high and leads to
hypercalcemic crisis
– Diagnosis is difficult and too often made after death
– Treatment is urgent
• Rehydration is vital.
• Biphosphonates -(disodium etidronate and pamidronate)
are specific inhibitors of bone resorption

15. • Clinical features
– Hyperparathyroidism is commoner in women than
men
– Clinical features are enormously variable
– Asymptomatic cases
• The most common presentation is the detection
hypercalcaemia by routine biochemical screening.
– Nonspecific symptoms
• Muscle weakness, thirst, polyuria, anorexia , weight
loss

16. • Clinical features…
– Bone disease - vague pains
1. Generalised decalcification
2. Single/multiple cysts, pseudotumour
– Renal diseases
1. Renal stones
2. Nephrocalcinosis
3. Hypertension
– Gastrointestinal Complications
1. Peptic ulcer disease
2. Pancreatitis
3. Cholelithiasis

17. • Clinical features…
– Neuropsychiatric Complications
1. Psychosis, obtundation, or coma
2. Depression, anxiety, and fatigue
3. Electroencephalogram abnormalities
– Other Features
1. muscle weakness
2. Chondrocalcinosis, gout, and pseudogout
3. Tissue calcium deposit (blood vessels, cardiac valves,
and skin)
4. LVH

18. • Physical Findings
– Palpable neck mass may be thyroid in origin or a
parathyroid cancer
– Corneal calcification
– Band keratopathy
– Fibro-osseous jaw tumors
– Electrocardiographic changes with a shortened
QT interval

19. • Differential diagnosis
– Secondary cancer in bone (breast, prostate, bronchus,
kidney and thyroid)
– Carcinoma with endocrine secretion (bronchus, kidney and
ovary)
– Multiple myeloma
– Vitamin D intoxication
– Sarcoidosis
– Thyrotoxicosis
– Immobilisation
– Medication: thiazide diuretics, lithium
• Parathormone is not detectable in the blood in the
above-mentioned conditions

20. • Laboratory Tests
– Serum calcium ↑↑
– PTH assays(immunoradiometric assays) - N or↑
– Serum phosphorus - ↓
– Hyperchloremic metabolic acidosis
– Alkaline phosphatase ↑ in bone diseases
• Imaging tests
– Hand and skull x-rays - may demonstrate osteitis
fibrosa cystica
– Abdominal ultrasound to document renal stones.

21. • Preoperative localisation
1. Non invasive
– Ultrasound scan
– Computerized tomography
– Thallium-technetium isotope subtraction imaging
– MRI
2. Invasive localization tests
– FNAB
– Angiogram
– Venous sampling
– Intraoperative PTH assay

22. • Treatment
– Surgery – is the only corrective treatment
– Postoperative vitamin D and calcium replacement
therapy is required for varying periods

23. • Parathyroid carcinoma
– Rare problem causing hyperparathyroidism
– neck irradiation is a risk factor for the development of
parathyroid adenomas not for carcinoma
– Presents with severe symptoms, serum calcium levels >14
mg/dL, significantly elevated PTH levels (5 x normal) and a
palpable parathyroid gland
– Local invasion is most common
– Tumor is gray-white to gray-brown intraoperatively
• Treatment
– Consists of bilateral neck exploration, with en bloc excision of
the tumor and the ipsilateral thyroid lobe
– Postoperative radiotherapy