Parathyroid gland M. Alhashash

Anatomy

Physiology

Parathyroid Imaging Tc-99m sestamibi scan (Cardiolyte) Ultrasound Initially thought useful only in persistent or recurrent disease. Thallium-technetium subtraction scan - now rarely used

Parathyroid Imaging - Tc-99m Sestamibi 45 min Anterior45 min LAO 2 HR submandibular gland thyroid lobe adenoma Delayed views

Disorders of Parathyroid Glands Hypoparathyroidism -rare. Almost always caused by excessive surgical removal of parathyroid tissue (iatrogenic) during thyroid or parathyroid surgery Hyperparathyroidism (HPT): – primary - high Ca++, high PTH - usually due to single adenoma (90%), cured by removal of adenoma – secondary - low Ca++, high PTH, seen in chronic renal failure - not a surgical problem – tertiary - high Ca++, high PTH, seen after renal transplant - hyperplasia of all 4 glands

Primary hyperparathyroidism The commonest. Autonomous production of PTH. Pathology: – Neoplasm(85%). Adenoma (80%) usually single gland Carcinoma (5%) usually associated with hyperplasia or adenoma. – Hyperplasia(15%)usually 4 glands and may be associated with MEN syndrome.

Primary hyperparathyroidism Clinically: – Females > males – Symptoms of hypercalcaemia. Abdomen: anorexia, nausia, vomiting, hypotonia---peptic ulcer---pancreatitis. Renal: stones, polyuria, nephrocalcinosis, renal failure, hypertension. Skeletal: intense bone resorption, pathological fractures, calcification of cartilages and pain. Psychotic: apathy, drowsiness and depression. General : weakness, pruritis, neuropathy, numbness, thirst, salivary gland calculi. Hypercalcaemic crisis: Ca > 15mg % confusion and coma.

Investigations Hypercalcaemia (normal Ca 9.2 – 10.4mg%). Hypophosphataemia. PTH Plain x-ray bone and stones U/S, CT, MRI, Isotope scanning

Treatment Hyperplasia subtotal parathyroidectomy. Adenoma resection of the affected gand/s. Carcinoma: hemithyroidectomy with the gland followed by radiotherapy. Hypercalcaemic crisis : I.V. phosphate, calcitonin, saline and diuretics.

Secondary hyperparathyroidism. In chronic renal failure -  hypocalcaemia-  hyperplasia of the gland. Clinically : mainly bone resorption. Treatment: mainly medical – Restriction of phosphate. – Calcium. – Vitamin D. – surgery only in severe cases by subtotal parathyroidectomy Localization as primary.

Tertiary hyperparathyroidism After renal transplantation Sever bone manifestation. Subtotal parathyroidectomy.

Traditional Surgery for Hyperparathyroidism primary HPT - 4 gland exploration, remove adenoma, biopsy 3+ normal glands tertiary HPT (after renal transplantation) - 3 1/2 gland removal +/- forearm autotransplant

Complications of Parathyroid Surgery persistent HPT % (experience dependent) temporary or permanent hypocalcemia % nerve injury - recurrent or superior laryngeal % bleeding - <5%

Unilateral Exploration for Primary HPT if: one abnormal, hypercellular gland and one normal gland found on one side, no contralateral exploration occasional use of preop thallium- technetium scan results of 5 studies - cure %

Parathyroid gland Thank you