Masters of Surgery Flashcards
Side effect of carbimazole and propylthiouracil?
Agranulocytosis (massive decrease in WBC)
What should you give people before thyroidectomy for hyperthyroidism?
Lugols iodine (potassium iodide) (reduces vascularity of gland) Beta-blocker to block the cardiovascular and CNS symptoms of the thyrotoxicosis
Complications of thyroidectomy surgery
Haemorrhage (can cause respiratory distress by tracheal compression)
Hypocalcemia (caused by damage to parathyroid glands)
Recurrent laryngeal nerve injury
Which fascia is the thyroid gland in?
The pretrachial fascia
Thyroglossal tract
Connects back of tongue to the thyroid gland
Key steps in evaulation of thyroid nodule or goitre?
Thyroid function tests (TSH, T3 and free T4)
Fine Needle Aspiration Cytology (FNAC):
-determines whether the follicular cells are benign, suspicious or malignant
Other useful tests:
- Thyroid ultrasound (cystic vs. nodule)
- Thyroid isotope scan –> useful if there is a solitary nodule and suppressed TSH, to look for a solitary toxic adenoma
Treatment of solitary thyroid nodule? (hint FNAC)
Treatment depends on FNAC result
If benign, the nodule can be left alone and repeat FNAC in 6-12 months
If FNAC is suspicious –> thyroid lobectomy is carried out as a quarter of these nodules are malignant
If FNAC is frankly malignant –> total thyroidectomy
If FNAC reveals a cyst:
small cyst (4cm) treated by thyroid lobectomy because of risk of malignancy
Papillary carcinoma
Most common and best prognosis
Disease spread to the lymph nodes and by direct invasion into the neck
Distant metastases are uncommon
Follicular carcinoma
Tumour develops later in life than papillary carcinoma
Spread mainly via the blood stream with distant metastases to bones, liver and brain
Medullary carcinoma
This is uncommon and develops from the calcitonin-secreting parafollicular cells
SOMETIME ASSOCIATED WITH TUMOURS IN THE PARATHYROID AND ADRENAL GLANDS –> MEN2
There may be a history of irradiation to the head and neck during childhood or a family history of thyroid carcinoma?
Thyroid cancer, shocker
Diagnosis of thyroid cancer
Thyroid function tests FNAC Chest radiograph (to look for pulmonary metastasis)
A high serum calcium level coupled with a low serum phosphate level is highly suggestive of what?
(primary) hyperparathyroidism
Parathyroid hormone effects on calcium and phosphate?
Mobilises calcium from bone
Reduced renal calcium excretion
Promotes renal phosphate excretion
Causes of primary hyperparathyroidism
Single parathyroid adenoma (most common: 85%)
Generalised parathyroid hyperplasia (15%)
Parathyroid carcinoma (1%)
Secondary hyperparathyroidism
This develops as a result of some of the complex metabolic changes associated with chronic renal failure, which tend to produce a low calcium level
Hypokalaemia and hypertension
Aldosteronism
This can present as a hypertensive crisis with sweating, palpitations, severe headache and occasionally an MI or cerebrovascular incident?
Phaeochromocytoma
This can present insidiously with diastolic hypertension
Phaeochromoctyoma
Treatment of Phaechromocytoma
Usually, alpha-adrenergic blockade (phenoxybenzamine) is started some time before surgery, with agents such as nitroprusside and propanolol being used to control blodd pressure and heart rate during the operation
Questions you should ask when taking a thyroid history?
Family history of thyroid disease
Past medical history of neck irradiation
Any history of hoarseness
- ask the patient to swallow
- ask the patient to stick out his tongue
Most common cause of subperiostal bone resorption in the phalanges?
Hyperparathyroidism
Hot and cold thyroid nodules?
Hot nodules usually associated with hyperthyroidism
Cold nodules usually associated with malignancy (or simple cysts)
Type of thyroid cancer that usually metastasises to the bone?
Follicular
Hyperaldosteronism and renin levels?
Low renin in PRIMARY hyperaldosteronism
High renin in SECONDARY hyperaldosteronism (caused by hepatic or renal disease)
A patient with Cushing syndrome may be diabetic?
True
Glucose intolerance and fasting hyperglycemia are common in Cushing syndrome
Measuring urea and electrolyes (low potassium)
Increased plasma aldosterone
Decreased plasma renin
Primary hyperaldosteronism
