Endocrine #3 Flashcards
What is a pheochromocytoma?
-Catecholamine secreting adrenal tumor (dopamine, norepinephrine, epinephrine)
True or False: 90% of pheochromocytoma are benign?
True
Only 10% are malignant
Triggers of a pheochromocytoma
- Surgery
- Exercise
- Pregnancy
- Medicaitons (TCA, opiates, histamine, glucagon)
Symptoms of a pheochromocytoma
- Hypertension (most consistent finding)
- PHE: Palpitations, headache (MC), excessive sweating
Confirmation diagnostic for pheochromocytoma
-24 hour urinary fractionated catecholamines including metabolites (increased metanephrines and vanillylmandelic acid)
Preoperative management for pheochromocytoma
- Nonselective alpha blockade (Phenoxybenazmine or Pehntolamine) for 1-2 weeks followed by beta-blockers to control BP
- DO NOT INITIATE THERAPY WITH BETA-BLOCKADE
Definitive management for pheochromocytoma
-Complete adrenalectomy after 1-2 weeks of medical therapy
Iatrogenic hypothyroidism is often due to
Treatment for hyperthyroidism with radioactive iodine or surgery without subsequent thyroid hormone replacement
Three medications that cause iatrogenic hypothyroidism
- Amiodarone
- Alpha-Interferon
- Lithium
What is cretinism?
Untreated congenital hypothyroidism
Etiologies of cretinism
- Lack of maternal iodine intake in developing countries
- Dysgenesis of thyroid gland in developed countries
Symptoms of cretinism
- Mental developmental delays
- Short stature
- Symptoms of hypothyroidism: cold intolerance, dry skin, constipation, weight gain, menorrhagia, weakness, lethargy
- Goiter symptoms: hoarseness and dyspnea
- Coarse facial features: macroglossia, hypotonia, umbilical hernia
Treatment for cretinism
Levothyroxine (synthetic T4)
What do labs for cretinism show?
Hypothyroidism labs: increased TSH and decreased free T3 and T4
MCC of hypothyroidism in the US
Hashimoto Thyroiditis
Pathophysiology of Hashimoto Thyroiditis
-Autoimmune thyroid cell destruction by anti-thyroid peroxidase an anti-thyroglobulin antibodies
Symptoms of Hashimoto Thyroiditis
- Symptoms of hypothyroidism
- Galactorrhea
- Goiter
- Bradycardia, loss of outer 1/3 of eyebrows
- Myxedema (non pitting edema - periorbital or peripheral)
What antibodies are present in Hashimoto Thyroiditis?
-Antithyroid peroxidase and/or anti-thyroglobulin antibodies
Although a biopsy is rarely done for Hashimoto Thyroiditis, what is seen if it is done?
-Lymphocytic infiltration with germinal centers and Hurthle cells (enlarged epithelial cells)
Treatment for Hashimoto Thyroiditis
-Levothyroxine
Levothyroxine is used first-line for Hashimoto and subclinical hypothyroidism with TSH _____ or greater
10 mIU/L or greater
Levothyroxine has a half-life of
7 days
What are the rules for monitoring with Levothyroxine?
- Monitor TSH levels at 6-week intervals when initiating or changing dose
- Increase dose if TSH is high and decrease dose if TSH is low
- During pregnancy, the dose needs to be increased
Adverse effects of Levothyroxine
-Overshoot can cause adverse cardiovascular effects and cause osteoporosis
What is euthyroid sick syndrome?
Abnormal thyroid function tests in patients with normal thyroid function
What lab is diagnostic for euthyroid sick syndrome?
Low T3 syndrome: decreased Free T3 and increased reverse T3 most common
What is Reidel Thyroiditis?
-Chronic autoimmune thyroiditis characterized by dense fibrosis that invades the thyroid and adjacent neck structures
Symptoms of Riedel Thyroiditis
- Rock hard, nontender, rapidly growing fixed goiter
- Airway compression
- No cervical LAD
What should be done to differentiate anaplastic thyroid carcinoma from Riedel Thyroiditis?
Open thyroid biopsy
What other lab should be done for Riedel Thyroiditis?
IgG4 serum levels
A myxedema coma is most commonly seen in
Elderly women with long-standing hypothyroidism during the winter
Treatment for myxedema coma
- IV Levothyroxine + supportive
- Passive warming
- IV Glucocorticoids
- ICU admission
What is subacute thyroiditis (DeQuervain Thyroiditis)?
-Often follows viral respiratory tracy infection or post-viral inflammation
Presentation of a patient with subacute thyroiditis?
- Hyperthyroidism is initial presentation
- Followed by euthyroid
- Then Hypothyroidism
- Then resolution and restoration of normal thyroid function
Symptoms of subacute thyroiditis
- Painful thyroid gland, diffusely tender goiter
- URI symptoms: fever, malaise, myalgias, fatigue
Diagnostics for subacute thyroiditis will show
High ESR + negative thyroid antibodies
However, a biopsy will for subacute thyroiditis will show
-Granulomatous inflammation with multinucleate giant cells
Treatment for subacute thyroiditis
- Supportive
- NSAIDs or Aspirin for pain
MCC of hyperthyroidism in the US
Graves Disease
Although Graves Disease has symptoms of hyperthyroidism such as _______, what are some symptoms that are specific to Graves Disease?
- Palpitations, heat intolerance, tremors, weight loss, atrial fibrillation
- Graves: Ophthalmopathy: proptosis, exophthalmos, lid lag, diplopia & Pretibial Myxedema
- Thyroid bruit
Diagnostics for Graves Disease
- Hyperthyroid profile: Low TSH and high T3/T4
- Thyroid stimulating immnoglobulins (TSH receptor antibodies) hallmark
Treatment for Graves Thyroid Disease
- Radioactive iodine: MC used
- Methimazole or PTU
However, for ophthalmopathy what is the best treatment
Glucocorticoids
Radioactive iodine is contraindicated in what people?
Pregnant and lactating women
_____ is generally the preferred treatment for Graves Disease; however, _____ is preferred in the first trimester and for thyroid storm
Methimazole
PTU
What is suppurative thyroiditis?
bacterial infection of the thyroid gland by Staph Aureus
Symptoms of suppurative thyroidits
- Thyroid pain and tenderness
- Overlying erythema to the skin
- Fever, chills, pharyngitis, dysphagia
What diagnostic should be done if you suspect suppurative thyroiditis?
Fine needle aspiration with Gram Stain and culture
The only two causes of a painful thyroid are ____ and _____
Subacute and Suppurative Thyroiditis
