Endocrine Surgery Flashcards
What is a summary of thyroid physiology?
TRH from hypothalamus stimulates release of TSH from anterior pituitary
Stimulating T4 and T3
There is a short and long feedback loop
What are thyroid hormone effects?
Increase in carbohydrate/ lipid catabolism
Increase protein synthesis
Increase in basal metabolic rate
Growth and maturation
Describe thyrotoxicosis
Clinical syndrome of excess circulating thyroid hormones - commonly due to hyperthyroidism
Primary - Graves disease
Secondary - TSHoma, thyroiditis
What is a goitre?
Enlargement of the thyroid gland
Endemic, sporadic and multinodular (most common)
Benign
What are types of thyroid neoplasms?
Adenomas
Carcinoma - papillary, follicular, medullary and anaplastic
What are the causes for goitre?
Genetics, MNG, AITD, iodine deficiency, malignancy and TSHoma
What is a sign of goitre?
Pemberton’s sign - red face if arms lift up as obstructed venous supply
Also can get stridor
What investigations are needed for goitre?
TFT, US and CT
What are the complications of a thyroidectomy?
Neck tension/ tenderness, voice problems, swallowing problems, irritated windpipe, haematoma, decreased PTH and recurrent laryngeal nerve injury
Explain thyroid cancer
Medullary arises from calcitonin secreting C cells
Usually good prognosis in papillary and follicular
Anaplastic very poor prognosis
Spreads to lymph nodes, bone and lungs
What is the investigation for thyroid cancer?
Fine needle aspiration cytology
What is the treatment for thyroid cancer?
Surgery and radio-iodine
What are parathyroid glands embryologically derived from?
Pharyngeal pouches and ultimobranchial body
Describe PTH physiology
PTH acts on kidneys and bone to release Ca and decrease excretion of Ca
Vit D goes to liver + kidneys and activated calcitriol acts on small intestine to increase dietary absorption of Ca + release Ca from bones
What are common primary disorders of parathyroid glands?
Adenoma, hyperplasia and carcinoma
What are secondary causes of hypercalcaemia?
Renal failure and hypo vitamin D
What surgery is used for parathyroid glands?
Targeted parathyroidectomy - one gland
Bilateral neck exploration
Describe the hormones of adrenal gland
Cortex
Zona glomerulosa - mineralocorticoids
Zona fasciculata - glucocorticoids
Zona reticularis - androgens and oestrogen
Medulla - epinephrine and norepinephrine
Describe Conn’s syndrome
Excess mineralocorticoids
Hyperalderonism
Increased Na reabsorption, increased K/H excretion and increased ECF volume
Hypertension and possible hypokalaemia
Describe the synthesis of catecholamines
Tyrosine - dopamine - norepinephrine and epinephrine
Tyrosine hydroxylase needed
Describe pheochromocytoma
Excess catecholamines
Medulla stimulated by sympathetic system
Extra adrenal chromaffin tissue
10% tumour - 10% familial, malignant, multiple and extra-adrenal
What are the symptoms and signs of pheochromocytoma?
Tachycardia, palpitations, pallor, tremor, headache and sweating
Hypertension, orthostatic hypotension, retinopathy, and fever
What are the investigations for pheochromocytoma?
Urine/ plasma metanephrines MIBG
Scans
Describe neuroendocrine tumours
Tumour of gut endocrine cells
Carcinoid - cancer like
Secrete serotonin and chromogranin
Measure urinary 5-HIAA and serum chromogranin
What are the clinical features of neuroendocrine tumours?
Asymptomatic and intestinal obstruction/ bleeding
Advanced disease - flushing, diarrhoea and bronchospasm
Describe pancreatic neuroendocrine tumours
Rare
Pancreatic endocrine cells
MEN Type I
Insulinoma - hypoglycaemia
Gastrinoma - peptic ulcer
Glucagonoma - DM, migratory skin erythema
Describe multiple endocrine neoplasia
Rare and autosomal familial syndromes
Endocrine tumours in multiple organs
Germline gene mutations
What is MEN1?
Tumour of parathyroid glands often accompanied with tumours of anterior pituitary + endocrine pancreas
What is MEN2?
Medullary thyroid cancer often accompanied with pheochromocytoma and parathyroid tumours
