Endo Patho Anki Flashcards
The main functions of the thyroid gland are brought by the two main parenchymal cell types: 1. […] 2. […]
The main functions of the thyroid gland are brought by the two main parenchymal cell types: 1. Follicular cells –> T3 and T4 thyroid hormones 2. Parafollicular C cells –> Calcitonin
Normal thyroid weighs about […] generally heavier in which gender? […]
Normal thyroid weighs about 20-25g generally heavier in which gender? women!
Clinical consequences of enlargement of thyroid (goiter)? […]
Clinical consequences of enlargement of thyroid (goiter)? 1. Breathing difficulty (compression on trachea) 2. Stridor (compression on trachea) 3. Swallowing difficulty (compression on esophagus) 4. Hoarseness of voice (recurrent laryngeal nerve compression) Think of it as DDD; dysphonia, dysphagia and dyspnoea. Mass effect!! Stridor = breathing sound due to large airway obstruction, usually worse
Main functions of thyroid hormone: 1. […] 2. […]
“Main functions of thyroid hormone: 1. Basal metabolic rate (BMR) - Heart rate - appetite - catabolism - protein synthesis 2. Growth and maturation - esp of CNS (deficient children will be short and have mental deficiency) (aka ““cretinism””)”
[…] is secreted by thyroid gland which is stimulated by […] secreted by anterior pituitary gland which is stimulated by […] secreted by hypothalamus
Thyroid hormone is secreted by thyroid gland which is stimulated by Thyroid stimulating hormone (TSH) secreted by anterior pituitary gland which is stimulated by Thyrotropin releasing hormone (TRH) secreted by hypothalamus
Thyroid hormone is secreted by […] which is stimulated by Thyroid stimulating hormone (TSH) secreted by […] which is stimulated by Thyrotropin releasing hormone (TRH) secreted by […]
Thyroid hormone is secreted by thyroid gland which is stimulated by Thyroid stimulating hormone (TSH) secreted by anterior pituitary gland which is stimulated by Thyrotropin releasing hormone (TRH) secreted by hypothalamus
Primary disease of thyroid is defined by […] Secondary disease of thyroid is defined by […]
Primary disease of thyroid is defined by disease occuring at thyroid itself - (TSH high T3 and T4 low (or vice versa)) Secondary disease of thyroid is defined by disease caused by malfunctioning of pituitary gland or hypothalamus - (TSH low, T3 and T4 low (or vice versa))
Calcitonin function: […]
“Calcitonin function: reduces calcium level in blood by 2 mechanisms: major: inhibiting osteoclast in bones, or minor: inhibit calcium tubular reabsorption ““importance of this role in humans is unclear, as patients who have very low or very high levels of calcitonin show no adverse effects.”””
2 categories of pathologies for thyroid diseases: 1. […] 2. […]
2 categories of pathologies for thyroid diseases: 1. Function abnormality (physiology) 2. Goiter (anatomy)
some signs and symptoms of (name 6 each) Hyperthyroidism […] Hypothyroidism […]
some signs and symptoms of (name 6 each) Hyperthyroidism - tachycardia - increased appetite - weight loss - heat intolerance - diarrhea - irritability (or nervousness or tremor)- warm and sweaty Hypothyroidism - bradycardia - decreased appetite - weight gain - cold intolerance - constipation - mental slowness - dry and cool If you need help just compare the following: 1. HR 2. Weight 3. Cold/ Hot
Biochemical test for thyroid function: checking the levels of 1. […] 2. […]
Biochemical test for thyroid function: checking the levels of 1. TSH (used to distinguish primary vs secondary thyroid disease) 2. free T4 Mainly the above. But also total T4, T3, autoantibodies.
Example of Primary Hyperthyroidism 1. […] 2. […] 3. […] 4. […] Primary Hypothyroidism 1. Hashimoto thyroid (autoimmune destruction of thyroid gland) - aka chronic lymphocytic thyroiditis) 2. Iatrogenic - thyroidectomy - Radiation therapy (eg. for cancer) - drugs especially iodide/ 131-I therapy 3. Congenital/Developmental - eg. hyperplasia, dysgenesis
Example of Primary Hyperthyroidism 1. Graves disease (autoimmune that stimulates T3 T4 production) - ophthalmapathy sign - autoantibodies - aka toxic diffuse goiter 2. Toxic multinodular goiter - MNG (thyroid gland that contains autonomously functioning thyroid nodules) 3. Toxic adenoma - eg. follicular adenoma 4. Exogenous thyroid hormone/ iatrogenic - eg. post-surgical Primary Hypothyroidism 1.
2 types of goiter and some examples: 1. […] 2. […]
2 types of goiter and some examples: 1. Diffuse - Graves disease - simple goiter due iodine deficiency - Dequervain’s thyroiditis (aka subacute granulomatous thyroiditis or giant cell thyroiditis) 2. Localised/Nodular - multinodular goiter (nodular hyperplasia) - Dequervain thyroiditis (thyroiditis) - Hashimoto’s disease (thyroiditis) - neoplastic
2 examples of benign thyroid neoplasms: […] 2 examples of well differentiated malignant thyroid follicular cells: - Papillary type carcinoma (#1) - Follicular carcinoma - Hurthle cell carcinoma 1 example of poorly/un- differentiated maligant thyroid follicular cells: - Poorly differentiated carcinoma (insular) - Anaplastic carcinoma 2 examples of non-follicular maligant thyroid neoplasm - Medull
2 examples of benign thyroid neoplasms: - Follicular adenoma - Hürthle cell adenoma 2 examples of well differentiated malignant thyroid follicular cells: - Papillary type carcinoma (#1) - Follicular carcinoma - Hurthle cell carcinoma 1 example of poorly/un- differentiated maligant thyroid follicular cells: - Poorly differentiated carcinoma (insular) - Anaplastic carcinoma 2 examples of non-follicu
4 etiological causes/ classifications of thyroid diseases 1. […] 2. […] 3. […] 4. […]
4 etiological causes/ classifications of thyroid diseases 1. Congenital anomalies 2. Hyperplasia (diffuse and nodular goitre) 3. Thyroiditis and Immune disorders (Hashimoto, Dequervain, Graves) 4. Neoplasms (adenoma, carcinoma, lymphoma) Similar concept to all other diseases: Infection, Autoimmune, Congenital, Metabolic, Neoplasm
Most common causes of Hyperthyroidism - […] - […] - […] Hypothyroidism - […] - […]
Most common causes of Hyperthyroidism - Graves disease (85%) - Multinodular goitre - Adenoma Hypothyroidism - Hashimoto thyroiditis (60%) - Iatrogenic
4 examples of congenital thyroid diseases 1. […] - Embryogenal vestige - can be complicated with infection/malignancy - Moves up when pt protrude tongue!! - Treatment: surgical excision 2. […] 3. […] 4. […]
4 examples of congenital thyroid diseases 1. Thyroglossal duct cyst - Embryogenal vestige - can be complicated with infection/malignancy - Moves up when pt protrude tongue!! - Treatment: surgical excision 2. Abnormal development of thyroid gland (aplasia/agenesis or hypoplasia) 3. Ectopic thyroid tissue (located at abnormal position) 4. Thyroid dyshormongenesis (not common) When asked about congen
Thyroid hyperplasia is commonly due to? […]
Thyroid hyperplasia is commonly due to? abnormal iodine availability or usage (it could also be due to ingestion of goitrogens, substances that interfere with thyroid hormone synthesis) A low amount of thyroxine (one of the two thyroid hormones, T4) in the blood, due to lack of dietary iodine to make it, gives rise to high levels of thyroid stimulating hormone (TSH), which stimulates the thyroid g
What is the pathogenesis for diffuse and multinodular goitre? […]
What is the pathogenesis for diffuse and multinodular goitre? Impaired synthesis of thyroid hormones (low iodine levels/iodine deficiency/goitrogens/congenital enzyme defects/AR) –> compensatory increase in TSH –> hypertrophy and hyperplasia of follicular cells –> enlargement of thyroid gland (diffuse goitre) –> recurrent hyperplasia and involution –> nodular enlargement (multinodular goitre)
MNG is an evolution from […], with extreme and irregular enlargements. What is the clinical significance of MNG? - […] - […] - […] - […] - […]
MNG is an evolution from simple goitre, with extreme and irregular enlargements. What is the clinical significance of MNG? - Commonest cause of goitre - May mimic neoplastic disease - Mass effects: compression of trachea, RLN (hoarseness), difficulty swallowing - Cosmetic issues - Toxic goitre –> hyperthyroidism
The commonest type of goitre is […]
The commonest type of goitre is MNG Dont forget that MNG can be mistaken for cancer!! Simple goitre is usually missed
Name 4 examples of thyroiditis - (AI) […] - (AI) […] - (Other thyroiditides) […] - (Other thyroiditides) […]
Name 4 examples of thyroiditis - (AI) Hashimoto thyroiditis - (AI) Graves disease - (Other thyroiditides) DeQuervain thyroiditis - (Other thyroiditides) Riedel thyroiditis googled:
Clinical presentation of DeQuervain thyroiditis (aka subacute granulomatous thyroiditis) - Usually seen after […] - usual women 30-50yo - short history - self limiting - usually not clinically apparent - systemic symptom (fever, malaise, etc.) - this goitre is TENDER. (most goitre not tender) Gross morphology: - Patchy - firm, pale and yellowish areas with intervening normal parenchyma. - Enlarg
“Clinical presentation of DeQuervain thyroiditis (aka subacute granulomatous thyroiditis) - Usually seen after viral infection (MCQ uses URTI as example) - usual women 30-50yo - short history - self limiting - usually not clinically apparent - systemic symptom (fever, malaise, etc.) - this goitre is TENDER. (most goitre not tender) Gross morphology: - Patchy - firm, pale and yellowish areas with i
Riedel thyroiditis is characterized by […] is commonly mistaken for […]
“Riedel thyroiditis is characterized by extensive fibrosis of thyroid and surrounding structures is commonly mistaken for thyroid carcinoma VERY RARE. Hard and FIXED. ““A rider with his thick biker jacket”””
Hashimoto thyroiditis is […] Most commonly seen in - […] - […] Outline the pathogenesis of Hashimoto thyroiditis […] […]
Hashimoto thyroiditis is immune mediated cytotoxic destruction of thyrocytes. Caused by both cellular and humoral immunity. See below. Most commonly seen in - women (common risk factor for all AI diseases) - 45-65yo Outline the pathogenesis of Hashimoto thyroiditis Immune mediated cytotoxic destruction of thyrocytes Sensitization of CD4+ Th cells to thyroid antigens –> CD8+ T cell mediated cell d
Hashimoto thyroiditis complications (IMPT!!!) - […] - […] - […]
Hashimoto thyroiditis complications (IMPT!!!) - hypothyroidism - risk of other autoimmune diseases (eg. DM type 1, SLE, Sjogren syn) - B cell lymphoma of thyroid (e.g MALT)
Name some examples of autoantibodies to TSH receptors (TRAb)in Graves Disease. Which one is the most specific? 1. […] 2. […] 3. […]
Name some examples of autoantibodies to TSH receptors (TRAb)in Graves Disease. Which one is the most specific? 1. Thyroid stimulating immunoglobulin (TSI) (most specific for Graves) 2. Thyroid growth stimulating immunoglobulins (TGI) 3. TSH-binding inhibitor immunoglobulin (TBH) Additional ones might be autoantibodies like anti-TPO and anti-thyroglobulin, which are seen in Hashimoto as well
Graves Disease T3/T4 level: […] TSH: […] Presents as diffuse goitre +/- bruit Clinical triad: - Hyperthyroidism - Infiltrative ophthalmopathy (protruding eyes) - Infiltrative dermopathy (pretibial myxoedema) - only minority Pathogenesis: autoantibodies to TSH receptor (TRAbs) - e.g. TSI thyroid stimulating immunoglobulin - TSI most specific for Graves’ - Mimics actions of TSH → increased relea
Graves Disease T3/T4 level: High TSH: Low (due to negative feedback) Presents as diffuse goitre +/- bruit Clinical triad: - Hyperthyroidism - Infiltrative ophthalmopathy (protruding eyes) - Infiltrative dermopathy (pretibial myxoedema) - only minority Pathogenesis: autoantibodies to TSH receptor (TRAbs) - e.g. TSI thyroid stimulating immunoglobulin - TSI most specific for Graves’ - Mimics actions
Difference between graves and hashimoto disease in terms of morphology. (IMPT!!!) […]
Difference between graves and hashimoto disease in terms of morphology. (IMPT!!!) - Hashimoto is pale due to lymphocyte infiltrate. - Graves is reddish, like a steak because of hyperplasia/vascularity
2 most common maligancy in thyroid 1. […] 2. […]
“2 most common maligancy in thyroid 1. Papillary Thyroid carcinoma (PTC) 2. Follicular Thyroid carcinoma (FTC) PTC is MOST common, and thankfully has the BEST prognosis among the thyroid carcinomas. Also well known for LYMPHATIC spread. Other keywords include RET, BRAF and its distinctive histo features that is a must know: - Finely dispersed chromatin (orphan annie eye or ground glass apperance-
Clinical presentation of benign neoplasms of thyroid 1. […] 2. […] 3. […]
Clinical presentation of benign neoplasms of thyroid 1. solitary painless nodule (classically single nodule) 2. usually COLD nodules 3. rarely hyperfunctioning A cold nodule is a thyroid nodule that does not produce thyroid hormone
Microscopically MIFC is similar to follicular adenoma except for […]
Microscopically MIFC is similar to follicular adenoma except for capsular/vascular invasion.
Prognosis of thyroid follicular carcinoma: MIFC: […] Widely invasive: […]
Prognosis of thyroid follicular carcinoma: MIFC: GOOD!! (unless vascular invasion) Widely invasive: moderate
A Hürthle cell is often associated with […] as well as […].
A Hürthle cell is often associated with Hashimoto’s thyroiditis as well as oncocytic change. (Hürthle cell adenoma and Hürthle cell carcinoma, a subtype of follicular thyroid cancer)
Papillary carcinoma high risk group: […]
Papillary carcinoma high risk group: 1. 20-40 or children 2. exposed to ionising radiation
clinical presentation for thyroid papillary carcinoma (PTC) 1. […] 2. […] 3. […]
clinical presentation for thyroid papillary carcinoma (PTC) 1. painless nodule (cold) 2. enlarged cervical lymph nodes due to lymphatic spread (unlike follicular carcinoma) 3. BAD - hoarseness, cough, dysphagia
Prognosis for papillary carcinoma: […]
Prognosis for papillary carcinoma: v good! Follicular carcinoma also quite good.
(IMPT!!!) Diagnosis of follicular carcinoma (FTC) defined by: […] Diagnosis of papillary carcinoma (PTC) defined by: […]
“(IMPT!!!) Diagnosis of follicular carcinoma (FTC) defined by: Capsular or vascular invasion Diagnosis of papillary carcinoma (PTC) defined by: Nuclear features even in absence of papillae - Finely dispersed chromatin (orphan annie eye or ground glass apperance) - Nuclear grooves (coffee bean appearance) - Pseudoinclusions (it looks like there’s cytoplasm in the nucleus, or ““trapped””) - Oval and
Poorly differentiated carcinoma aka insular carcinoma spreads mainly by […] - […] - […] - […] Micro histology: - […]
Poorly differentiated carcinoma aka insular carcinoma spreads mainly by lymphatics and blood vessels - Invasive - May co-exist with well differentiated carcinomas (PTC, FTC) - Prognosis is between WDTC and anaplastic TC Micro histology: - Growth in large islands
Thyroid Medullary carcinoma refers to NET of the […] Clinical indications - […] (most impt!) - […] - […] - look out for […]
Thyroid Medullary carcinoma refers to NET of the parafollicular C cells Clinical indications - Raised serum calcitonin (most impt!) - paraneoplastic syndrome - mass - look out for MEN syndrome (very associated with family history!) The MEN (multiple endocrine neoplasia) syndromes are conditions which cause overactivity and enlargement in certain endocrine glands. MEN syndromes are usually (but not
Thyroid carcinoma spread (IMPT!!!) PTC: […] FTC: […]
Thyroid carcinoma spread (IMPT!!!) PTC: Lymphatic (to lymph node) FTC: Blood (to bone) PTC lymph, FTC Blood
Thyroid lymphoma usually arises in the background of which disease? […] Red flag: […]
Thyroid lymphoma usually arises in the background of which disease? Hashimoto thyroiditis!!! Red flag: Recent enlargement in elderly patients Recall that thyroid lymphomas are a complication of Hashimoto
forms of calcium in the body […]
forms of calcium in the body - bound to albumin - ionized - complexes Therefore TOTAL calcium might not be the amount of calcium that’s active only 1% of body calcium is in circulation, and only ~50% of this 1% is active (ionised)
Name the important hormones that affect calcium regulation […]
Name the important hormones that affect calcium regulation - PTH - Vit D - Calcitonin - Thyroid hormones - Adrenal hormones - Prostaglandins - Osteoclast activating factor In decreasing importance
PTH is produced by the […] and degraded mainly in the […]
PTH is produced by the parathyroid gland and degraded mainly in the kidney
PTH is cleaved within circulation to form 2 fragments, the C and N terminal. […] activity at N terminal […] activity at C terminal
PTH is cleaved within circulation to form 2 fragments, the C and N terminal. Biological (attaches to receptors) activity at N terminal Immunological activity at C terminal
PTH secretion is controlled by - […] - […] - […]
PTH secretion is controlled by - ionised calcium concentration - 1,25 dihydroxyvitamin D - magnesium (as a cofactor)
Actions of PTH (IMPT!!!!) Bone - […] Kidney - […] and - […] - […]
Actions of PTH (IMPT!!!!) Bone - stimulate bone resorption to mobilize its calcium and phosphate Kidney - increase distal nephron calcium reabsorption and - phosphate excretion at proximal tubule - Promotes formation of 1,25-dihydroxyvitamin D from 25-OHD TLDR, PTH increases Ca2+ Increased Ca2+ absorption in intestines is mediated via the 1:25 dihydroxyvitamin D produced in the kidneys
Name 5 examples that causes hypercalcemia 1. […] 2. […] 3. […] 4. […] 5. […] 6. […] 7. […] 8. […]
Name 5 examples that causes hypercalcemia 1. HyperPTH (pri, ter) 2. Malignancy (Multiple myeloma, humoral hypercalcaemia of malignancy, met to bone, eroding the bones) 3. Vitamin D excess (sarcoidosis, vit D intoxication) 4. Milk alkali syndrome 5. Immobilisation 6. Familial hypocalciuric hypercalcaemia 7. Endocrine disorders 8. Drugs Hyperparathyroid AND Malignancy most common
“Clinical features of hypercalcaemia (““stones, bones, moans (psychiatric), groans (abdominal)”” - Renal (stones, thirst, polyuria) - Bones - GI (e.g anorexia, abdominal pain) - Neurological (eg. fits, confusion, irritability) - Cardiac (eg. arrythmia) What are the clinical features of hypocalcaemia then? […]”
“Clinical features of hypercalcaemia (““stones, bones, moans (psychiatric), groans (abdominal)”” - Renal (stones, thirst, polyuria) - Bones - GI (e.g anorexia, abdominal pain) - Neurological (eg. fits, confusion, irritability) - Cardiac (eg. arrythmia) What are the clinical features of hypocalcaemia then? SAME! Interestingly, hypocalcaemia give the SAME symptoms as hypercalcaemia can deduce becaus