Thyroid Flashcards
Jod-Boseman phenomenon?
Iodine-induced Hyperthyroidism
Cardiac Complications of Hyperthyroidism?
- Increased heart rate, contractility, cardiac output
- Cardiomegaly
- Hypercalcemia-induced ECG changes (d/t bone turnover)
- Arrhythmia
Nervous System Complications of Hyperthyroidism?
- Fine tremor (hands)
- Anxiety
- Insomnia
- Emotional lability
- Inability to concentrate
- Brisk deep tendon reflexes
GI Complications of Hyperthyroidism?
- Malabsorption
- Diarrhea
Endocrine Complications of Hyperthyroidism?
- Increased bone turnover -> Osteoporosis
- Oligomenorrhea
Clinical Presentation of Hyperthyroidism?
- Increased Basal Metabolic Rate, Tachypnea
- Weight loss
- Myopathy (muscle weakness)
- Heat Intolerance
Diagnostic tests for Hyperthyroidism?
TSH, T3, T4
- Primary Hyperthyroidism: Decreased TSH
- Secondary Hyperthyroidism: Increased TSH
Treatment for Hyperthyroidism?
- β-blockers
- Thioamides
- High-dose iodide
- Radioactive iodine (131I)
Additional Lab Findings in Hyperthyroidism?
- Hypercalcemia due to increased bone resorption
- Hyperglycemia due to increased glycogenolysis and impaired peripheral insulin activity
- Hypocholesterolemia due to increased low density lipoprotein (LDL) receptor synthesis
Neurologic Complications in Hypothyroidism?
- Slow deep tendon reflexes,with a prolonged relaxation phase
- Fatigue and lethargy
- Mental slowness
- Perinatal intellectual disability
Cardiac Complications in Hypothyroidism?
- Bradycardia
- Decreased Contractility, Stroke Volume, Cardiac Output
- Increased LDL levels
Dermatologic Complications in Hypothyroidism?
- Coarse, brittle hair andnails
- Dry, sometimes yellow skin
- Facial & periorbital myxedema
Endocrine Complications of Hypothyroidism?
Hyperprolactinemia
GI Complications of Hypothyroidism?
Constipation (d/t decreased gut motility)
Only serious complication of Hypothyroidism?
Myxedema Coma
Clinical Presentation of Myxedema Coma?
- Hypothermic stupor/coma
- Hypoventilation with CO2 retention
- Hypotension
Treatment of Myxedema Coma?
- Respiratory support
- Intravenous levothyroxine
- Cortisol
Causes of Primary Hypothyroidism?
- Iodine deficiency
- Hashimoto thyroiditis (chronic autoimmune thyroiditis)
- Surgical thyroid removal or thyroid ablation (surgical orI-131 radiation)
- Drugs(notably lithium, amiodarone or sulfonamides)
- Other types of thyroiditis (subacute lymphocytic, subacute granulomatous,Riedel’s etc)
Clinical Presentation of Congenital Hypothyroidism?
- Poor brain development
- Pot-bellied
- Pale
- Puffy-faced
- Protruding umbilicus
- Protuberant tongue
Serum TSH levels seen in primary, secondary, and tertiatry hypothyroidism?
-Primary hypothyroidism (caused by thyroid hypofunction),TSH levels will be increased.
- ## Secondary hypothyroidism (caused by pituitary hypofunction), TSH levels will be decreased.Tertiary hypothyroidism: (caused by hypothalamic hypofunction),TSH levels will benormal/low-normal,
Clinical Presentation of Acute Thyrioditis?
- Fever
- Painful thyroid
- Painful cervical lymphadenopathy
Cause of Subacute Granulomatous Thyroiditis (DeQuervian)?
- Mumps
- Coxsackie virus
Clinical Presentation of Subacute Granulomatous Thyroiditis?
- Sore throat and fever
- Jaw pain
- Tender thyroid
- Elevated ESR
- No lymphadenopathy
Treatment for Subacute Granulomatous Thyroiditis?
- Aspirin
Usually Self-limiting within weeks
Clinical Presentation of Subacute Lymphocytic Thyroiditis?
Non-tender thyroid in postpartum women
What is Riedel Thyroiditis?
When Fibrous tissue replaces thyroid paremchyma-> Hypothyroidism
Physical Exam Findings in Riedel thyroidiits?
- Rock hard, fixed thyroid
- Painless
Etiologies of Primary Adrenal Insufficiency?
- Adrenal atrophy orautoimmune destruction
- Granulomatous infection (eg,tuberculosis)
- Metastasis to adrenal glands (Lung, breast cancers)
- HIV
- Infarction of the adrenal gland
- Waterhouse-Friderichsen syndrome
- Disseminated intravascular coagulation
Manifestations of decreased aldosterone and cortisol in Primary Adrenal Insufficiency?
- Hyponatremia (volume contraction →HYPOtension)
- Hyperkalemia
- Hypoglycemia
- Increased skin pigmentation*
Causes of Secondary Adrenal Insufficiency?
Insufficient ACTH secretion from pituitary
Manifestations of decreased cortisol (aldosterone is normal) in Secondary Adrenal Insufficiency?
- Hypoglycemia
- Low testosterone
Diagnostic Testing for Adrenal Insufficiency?
- 8 AM serum cortisol
- Plasma ACTH levels
- ACTH (cosyntropin) stimulation test
What is indicated if a ACTH analog is given and there is no increase in cortisol levels?
Primary Adrenal Insufficiency
ACTH, Aldosterone, Renin levels in Primary Adrenal Insufficiency?
- Elevated ACTH
- Low aldosterone
- Elevated renin
ACTH, Aldosterone and Renin levels in Secondary Adrenal Insufficiency?
- Decreased ACTH
- Normal aldosterone
- Normal renin
Most severe complication of adrenal insufficiency?
Shock (Adrenal Crisis)
What is the next best step for a thyroid nodule with Normal/Elevated serum TSH levels? Low TSH levels?
- Normal/Elevated: Fine Needle Biospy
- Low: Thyroid Scintigraphy (Contraindicated in pregnancy)
Ultrasound Findings of a thyroid nodule that are suggestive of a malignancy?
- Hypoechoic nodule
- Microcalcifications
- Progressive growth
- Extrathyroidal extension
- Irregular margins(infiltrative,microlobulated)
Hypocalcemia caused the release of what hormone?
Parathyroid Hormone (PTH)
Functions of Parathyroid Hormone (3)?
Aim to increase Serum Calcium:
- Increase Calcium reabsorption in Distal Convoluted Tubule
- Increase Calcium absorption in Intestines (by conversion of 25-OH Vit D to active 1,25 (OH)2 Vit. D)
- Decrease Phosphate Reabsorption
- Increase bone resorption (->Osteoclast Proliferation)
Diagnostic Workup for Thyroid Cancer?
1) Serum TSH
2) Ultrasound
3) Fine needle biopsy
4) Radionucleotide Scan
Factors that are indicative of Thyroid Cancer?
- Solid nodule palpated or seen on US
- Age (20-60) and increases with age
- Male
- Cold nodule on scintigram
- History of neck irradiation
The following histopathological findings are present in which thyroid carcinoma?
- Intranuclear cytoplasmic inclusions (“Orphan Annie eyes”)
- Psammoma bodies (concentric calcium collections)
- Nuclear grooves
Papillary Carcinoma
- Lymphatic Spread*
- Excellent Prognosis*
MEN2A and MEN2B are associated with which thyroid carcinoma?
Medullary Carcinoma
Clinical Manifestations of Medullary Carcinoma?
- Malignant Parafollicular Cells
- Cells stain positive for Amyloid
Surgical Invention in the presence of Thyroid Carcinomas?
- Surgical removal plus radioactive iodine ablation
- Lobectomy if nodule <1cm
- Total thyroidectomy if >1cm
Patient placed on Levothyroxine
