chem path Flashcards
the normal range for serum osmolality is
275 – 295 mmol/kg
formula for osmolarity
2(Na+ + K+) + urea + glucose
acromegaly ix + mx
OGTT (gold standard), IGF1 (only good for f/u after Dx)
Management:
1. Transsphenoidal Surgery (best)
2. Pituitary Radiotherapy
3. Cabergoline
4. Octreotide (expensive) – somatostatin analogue (can’t stop once started)
5. GH antagonist – pegvisomant
most common antithyroid medication
Carbimazole
how does goitre feel in graves?
painless
outline different causes of hyperthyroid
Graves disease: 40 - 60%, F>M (9:1), painless goitre, anti-TSH receptor Abs, high diffuse uptake on isotope scan (with Tc99)
Toxic multinodular goitre (Plummer’s): 30 - 50%, high uptake hot nodules, painless, enlarged follicular cells distended with colloid + flattened epithelium
Toxic adenoma: 5%, solitary ‘hot nodule’ on isotope scan (1 area of uptake)
Subacute De Quervains thyroiditis: self-limiting post viral painful goitre. Initially hyperthyroid, then hypothyroid
Postpartum thyroiditis (like De Quervain’s but postpartum)
Ectopic: trophoblastic tumour, struma ovarii (excessive hCG)
outline different causes of hypothyroid
Primary atrophic hypoT (commonest cause in UK): diffuse lymphocytic infiltration causing atrophy. No goitre so small thyroid. No known antibodies detected yet, associated with pernicious anaemia/vitiligo/endocrinopathies
Hashimoto’s thyroiditis: Plasma cell infiltration & goitre. Elderly females. May be initial ‘Hashitoxicosis’. ++ Autoantibody titres (anti TPO/TG), Hurthle cells, painless. goitre
Iodine deficiency (common worldwide)
Post thyroidectomy/radioiodine
Drug induced – antithyroid drugs, lithium, amiodarone
Riedel’s thyroiditis: dense fibrosis replacing normal parenchyma, painless, stony hard
most common type of thyroid neoplasia
papillary
tumour markers for differnt types of thyroid cancer
papillary = thyroglobulin
follicular = thyroglobulin
medullary = calitonin / CEA
