Thyroid - clinical Flashcards
Specific clinical manifestations of hypothyroidism?
Coarse hair Coarse skin Puffy facies Macroglossia Hoarse voice
What is macroglossia?
Unusually large tongue
Non-specific clinical manifestations of hypothyroidism
Bradycardia Constipation Cold intolerance Weight gain Tired
Hypothyroidism is usually…
Primary autoimmune
Primary AI causes of hypothyroidism?
Atrophic thyroiditis
Hashimoto’s thyroiditis
What blood test result do both atrophic thyroiditis and Hashimoto’s thyroiditis share?
Presence of thyroid peroxidase antibodies (TPO abs)
Differential diagnosis between atrophic thyroiditis and Hashimoto’s thyroiditis?
Hashimoto’s causes enlargement of the thyroid
Cause of primary hypothyroidism?
Lack of thyroid hormones causing a slowing of metabolic processes
Features of atrophic thyroiditis?
Fibrosis of thyroid gland and myxoedema
What is central hypothyroidism?
Hypothyroidism arising from a lack of TSH
What other investigations should be done in the case of central hypothyroidism?
Measure other pituitary hormones as well as testosterone
MRI/CT of the head (pituitary and hypothalamus)
Gene analysis
Treatment for hypothyroidism?
Levothyroxine
Thyrotoxicosis is…
Hyperthyroidism
Symptoms of thyrotoxicosis
Restlessness Warmth intolerance Diarrhoea Sweating Palpitations and breathlessness Mood and behaviour change Muscle stiffness and weakness
Clinical signs of hyperthyroidism?
Lid retraction
Lid lag
Causes of hyperthyroidism?
Grave’s disease
Toxic thyroid nodule
Cause of Grave’s disease?
Stimulating antibodies to the TSH receptor
Associated findings in Grave’s disease?
Orbitopathy (25%)
Dermopathy (orange peel) and acropachy (rare)
Elephantitis
Myxoedema
Why does the thyroid enlarge in Hashimoto’s?
Lymphocytic infiltration and destruction of thyroid tissue with secondary antibodies to TPO
Treatment for hyperthyroidism?
Carbimazole and Propylthiouracil
Radio-iodine (avoid in thyroid eye disease)
Surgery
Painless thyroiditis:
Hashimoto’s
Lymphocytic (post-partum)
Reidel’s (fibrous)
Painful thyroiditis:
Granulomatous (De Quervain’s)
Radiation-induced thyroiditis
Lump but TFTs normal and Abs not found?
Nodule: cytology and Ultrasound scan
Thyroid cancers
Papillary (PTC) - 85%
Medullary (linked with MEN2) - tumour marker is calcitonin
Anaplastic (lymphoma) - very aggressive
Hormone profile of primary hyperparathyroidism?
PTH: elevated
Ca: elevated
Phosphate: low
Urine Ca:Creatinine clearance > 0.01
Hormone profile of secondary hyperparathyroidism?
PTH: elevated
Ca: low or normal
Phosphate: elevated
Vitamin D: low
Hormone profile of tertiary hyperparathyroidism?
PTH: elevated Ca: normal or high Phosphate: low or normal Vitamin D: low or normal Alkaline phosphatase: elevated
What causes primary hyperparathyroidism?
Adenoma (mainly solitary)
Carcinoma
What causes secondary hyperparathyroidism?
Parathyroid hyperplasia due to low calcium almost always in the context of chronic renal failure
What causes tertiary hyperparathyroidism?
Continual hyperplasia (all 4 glands) despite correction of the underlying renal problem
Clinical signs of primary hyperparathyroidism?
Can be subtle or asymptomatic
Recurrent abdominal pain (renal colic, pancreatitis)
Changes in cognition/emotional state
Clinical signs of secondary hyperparathyroidism?
Few symptoms Eventually may develop: Bone disease Osteitis fibrosa cystica Soft tissue calcifications
Clinical signs of tertiary hyperparathyroidism?
Metastatic calcification
Bone pain and/or fracture
Nephrolithiasis
Pancreatitis
Finding of calcium:creatinine clearance < 0.01
Benign familial hypocalciuric hypercalcaemia
Histological finding in muscle cells of Thyroid disease myopathy
Checkerboard appearance due to areas of necrosis and regeneration
Causes of hypothyroidism:
Hashimoto's de Quevain's Postpartum thyroiditis Riedel's Iodine deficiency Lithum (Amiodarone - both)
Causes of hyperthyroidism:
Grave’s disease
Toxic multi nodular goitre
(Amiodarone - both)
(Postpartum and de Quervain’s both have an initial hyperthyroid phase before becoming hypo)
Investigation of thyrotoxicosis will reveal…
TSH down T3 and T4 up Thyroid autoAbs (Can do isotope scan)
Major active thyroid hormone:
T3
Plasma thyroid hormone (less potent):
T4
Lowers plasma calcium:
Calcitonin
What is associated with Hashimoto’s?
MALT lymphoma
High TSH
Low T3, T4
Anti-TPO +ve
Anti-Tg +ve
Hashimoto’s
Hashimoto’s increases your risk of:
Other AI conditions:
e.g. Addison’s, LE, Grave’s, T1DM, pernicious anaemia, RA, thrombocytopenic purpura, vitiligo
Features of Hashimoto’s thyroiditis?
Hypothyroid features
Firm, non-tender goitre
Anti-TPO and anti-Tg +ve
Signs of hypoparathyroidism:
Tetany: muscle cramping, twitching and spasm
Perioral paraesthesia
Trosseau’s sign: carpal spasm if brachial artery occluded by raising and holding pressure over systolic
Chvostek’s sign: tapping over the parotid causes facial muscle twitching
Chronic: depression, cataracts
ECG: prolonged QT interval
Treatment for primary hypoparathyroidism:
alfacalcidol
