Hypothyroidism

Hyperthyroidism or Hypothyroidism? a) coarse, brittle hair b) myopathy and normal CK c) constipation d) diastolic hypertension e) systolic hypertension f) puffy face

a) hypo b) hyper c) hypo d) hypo e) hyper? f) hypo

Hashimoto's Thyroiditis has an association with which HLA genes?

association with HLA-DR3, DR5 genotype

A 67-year-old woman has had fatigue, dry skin, brittle hair, swelling of the ankles, and cold intolerance for 1 year; she has gained 9 kg (20 lb) during this period. Her pulse is 55/min, and blood pressure is 150/90 mm Hg. She appears lethargic. Examination shows dry skin and a nontender thyroid gland that is enlarged to two times its normal size. There is mild edema of the ankles bilaterally. The relaxation phase of the Achilles reflex is greatly prolonged. Which of the following is the most likely diagnosis? (A) Chronic lymphocytic thyroiditis (Hashimoto disease) (B) Defect in thyroxine (T4) biosynthesis (C) Graves disease (D) Multinodular goiter (E) Riedel thyroiditis (F) Thyroid cyst (G) Thyroid lymphoma (H) Thyroiditis

(A) Chronic lymphocytic thyroiditis (Hashimoto disease)

A 62-year-old woman comes to the physician for a routine health maintenance examination. On questioning, she has had fatigue, constipation, and a 9-kg (20-lb) weight gain during the past year. She receives estrogen replacement therapy. Serum lipid studies were within the reference range 5 years ago. She is 157 cm (5 ft 2 in) tall and weighs 77 kg (170 lb); BMI is 31 kg/m2. Physical examination shows no other abnormalities. Serum lipid studies today show: Total cholesterol 269 mg/dL HDL-cholesterol 48 mg/dL LDL-cholesterol 185 mg/dL Triglycerides 180 mg/dL Which of the following is the most likely cause? (A) Alcohol (B) Diabetes mellitus (C) Estrogen deficiency (D) Estrogen replacement therapy (E) Hypothyroidism (F) Thiazide diuretic therapy

(E) Hypothyroidism This is a sample Step 2 USMLE.org question. How can we eliminate the other choices

Congenital Hypothyroidism (Cretinism)

* *Most common treatable cause of mental retardation *Untreated Congenital hypothyroidism results in Cretninism *The features of Cretinism are remembered using the 9 Ps. It is also associated with goiter, hernias, and coarse facies, **The vast majority of infants with congenital hypothyroidism are asymptomatic at birth.* **Decreased T4; Increased TSH (causing goiter)* *Prevention by newborn screening by law *Tx: Levothyroxine replacement

Hashimoto Thyroiditis

*AKA Chronic lymphocytic thyroiditis *Autoimmune disease that results in gradual destruction of the thyroid gland **Most common cause of Hypothyroidism in areas where iodine is sufficient* *Most frequently seen in middle aged women (45-65 = peak age) *Associated with HLA-DR5 *Associated with other autoimmune diseases (i.e T1DM, Pernicious Anemia, Sjogren's, **Enlargement of gland is usually insidious, symmetric, and diffuse* **Pathophysiology: Thyroid cell death results from a failure of self-tolerance to thyroid auto-antigens: Type 2 and 4 Hypersensitivity* *

Subacute Lymphocytic Thyroidits

*AKA Silent Thyroiditis *Clinically resembles Subacute thyroiditis (Early on may be hyperthyroid but later becomes hypothyroid) but histologically resembles Hashimoto (extensive lymphocytic infiltration without Hurthle Cell changes) *Associated with HLA-DR3; Suggests autoimmune etiology *Antimicrosomal antibodies may be elevated but will not be as high as that seen in Hashimoto *Decreased radioiodine uptake during hyperthyroid phase (used to differentiate from Grave's) *When it occurs after postpartum ,it is referred to as postpartum thyroiditis (usually within 3 months) *Tx: Symptomatic relief, including NSAIDs for pain and beta blockers for hyperthyroid symptoms

Describe the Histological findings of Hashimoto's Thyroiditis

*Extensive lymphocytic infiltrate with germinal center formation *Atrophic follicles with abundant Hürthle cells *Fibrosis may be increased but does not extend beyond capsule (Unlike Riedel's which does extend)

Describe the Histological findings of Subacute Granulomatous Thyroiditis

*Patchy infiltrate of lymphocytes, macrophages, and plasma cells *Granulomatous inflammation: Multinucleated giant cells enclosing colloid *Microabscesses may form *Fibrosis may appear Picture: The release of colloid into the interstitial tissue has elicited a prominent granulomatous reaction, with foreign body giant cells (Top left)

Myxedema Coma

*Result of severe, long-standing, untreated hypothyroidism *Usually precipitated by infection, stroke, heart failure, trauma, or CNS depressants *Characterized by -depressed mental status(more susceptible to overdosing of medications particularly sedatives, hypnotics due to decreased drug metabolism -respiratory depression/hypoventilation(CO2 retention) -Decreased cardiac output and contractility can cause hypotension -Hyponatremia (increased ADH due to decrease GFR) -*Hypothermia (decreased BMR in all tissues)* *High mortality rate because it predominantly affects elderly *Tx: High doses of T3 and T4

Subacute granulomatous thyroiditis (de Quervain)

*Self-limiting hypothyroidism following a viral infection (URI: Coxsackievirus, mumps, measles, adenovirus) *Early on may be hyperthyroid but later becomes hypothyroid (similar to Hashimoto's) *Rare, much less common than Hashimoto's thyroiditis *Most common cause of thyroid pain (may radiate to neck or jaw) **In subacute granulomatous thyroiditis there is no lymphadenopathy* *Preceded by a flu-like illness including symptoms of jaw pain *Histology: numerous non-necrotizing granulomas with multinucleated giant cells eating the colloid, stromal fibrosis and acute inflammation with microabscesses. **Associated with a decrease of Iodine uptake during the hyperthyroid phase* *ESR is elevated *Typically self-limited and resolves after weeks *Tx: Symptomatic relief, including NSAIDs for pain and beta blockers for hyperthyroid symptoms

Riedel Thyroiditis

*This is a fibrosing process of unknown etiology *Characterized by replacement of thyroid parenchyma by dense fibrous tissue *Distinguished from other fibrotic processes of the thyroid by extending beyond the capsule and into adjacent structures of the neck *Complications include: Hoarseness (recurrent laryngeal involvement), Stridor (tracheal compression), Airway obstruction **Most patients are euthyroid but hypothyroidism occurs in 30%* **Considered a manifestation of IgG4 related systemic disease: characterized by IgG4 positive plasma cells* *1/3 of patients will develop at least 1 extracervical manifestation of multifocal fibrosclerosis (retroperitoneal fibrosis, mediastinal fibrosis, or sclerosing cholangitis) Tx: Tamoxifen, Corticosteroids

Which of the following is NOT an expected histological finding in the thyroid of a paitient with Hashimoto's Thyroiditis? 1. Multinucleate giant cells 2. Lymphocytic infiltration 3. Several germinal centers 4. Fibrosis 5. Hurthle cells

1. Multinucleate giant cells

A obstetrician is working in a developing country to help promote maternal health and fetal well being. While there, he delivers a baby who he suspects has congenital hypothyroidism, most likely caused by inadequate maternal iodine intake. Which of the following signs and symptoms would NOT be expected to be observed in this child? 1. Hypotonia 2. Diarrhea 3. Umbilical hernia 4. Mild jaundice 5. Macroglossia

2. Diarrhea

You are working up a 6-week-old American infant in the pediatric clinic. He was born at term following an uncomplicated pregnancy and now lives with his parents in Massachusetts. However, his chart reveals an indirect hyperbilirubinemia present at birth. His mother reports poor feeding. On physical exam you note lethargy, hypotonia, a large, protruding tongue and coarse facial features. Which of the following is the most likely cause of this presentation? 1. Iodine deficiency 2. Thyroid dysgenesis 3. Rett syndrome 4. Trisomy 21 5. Toxoplasmosis

2. Thyroid dysgenesis The child in this vignette most likely has cretinism caused by untreated congenital hypothyroidism as a result of thyroid dysgenesis, the most common cause of cretinism in the developed world. Cretinism is a condition that develops in children who lack sufficient amounts of thyroid hormone. The classic presentation is a child who appears normal at birth (as there is maternal thyroid hormone present) but gradually develops lethargy, hypotonia, coarse facial features, and poor feeding over the next 6-12 weeks. Cretinism can also be caused by iodine deficiency, the most common cause in the developing world. Congenital hypothyroidism can be caused by agenesis of thyroid tissue or defects in the enzymes responsible for thyroid hormone production. T4 is crucial during the first two years of life for normal brain and bodily development.

MEN 2A vs MEN 2B

2A Medullary carcinoma of the thyroid Pheochromyctomas 2B Medullary carcinoma of the thyroid Pheochromyctomas Ganglioneuromas (of oral mucosa)

A 40-year-old female presents to your office complaining of a tender neck and general lethargy. Upon further questioning, she reports decreased appetite, fatigue, constipation, and jaw pain. Her pulse is 60 bpm and her blood pressure is 130/110 mm Hg. Biopsy of her thyroid reveals granulomatous inflammation and multinucleated giant cells surrounding fragmented colloid. Which of the following likely precipitated the patient's condition: 1. Iodine deficiency 2. Goitrogens 3. Thryoglossal duct cyst 4. Infection 5. Chronic renal disease

4. Infection Granulomatous inflammation and multinucleated giant cells around fragmented colloid are histologic features of subacute thyroiditis (de Quervain's thyroiditis). Subacute thyroiditis typically follows viral illnesses. The disease may manifest as hyperthyroidism early in its course but most often presents as hypothyroidism with findings of general lethargy and fatigue similar to those seen in the above patient.

A 45-year-old female presents to your office with a 2-week history of a painful mass in her neck after having a sore throat and fever for 3 days. The patient reports the mass has slowly been enlarging over that time span, and has become more painful to the touch. She also reports feeling hot even when her coworkers feel cold, and also reports loose stools over the past week. The patient's vital signs are T 37 C, BP 140/90, P 110 bpm, O2 100%. On exam, you note a goiter that is painful to the touch. TSH is decreased, T4/T3 is elevated, and radioactive iodine uptake and scan at 24 hours reveals an uptake of 3%. What is the next step in treatment? 1. Prednisone 2. Propylthiouracil 3. Radioactive iodine ablation 4. Symptomatic relief 5. Observation

4. Symptomatic relief The patient presents with subacute granulomatous thyroiditis (also known as de Quervain's thyroiditis). First-line treatment involves symptomatic relief, including NSAIDs and beta blockers.

Patients with Hashimoto's Thyroiditis have antibodies to?

85% of patients with Hashimoto thyroiditis have antibodies to various thyroid antigens, the most frequently detected of which include anti-thyroid peroxidase (anti-TPO) (also called antimicrosomal antibodies) antithyroglobulin (anti-Tg), and to a lesser extent, TSH receptor-blocking antibodies (TBII). Nevertheless, a small percentage of patients with Hashimoto thyroiditis (approximately 10-15%) may be serum antibody negative.

What is Dyshormonogenetic goiter?

A rare predominantly AR inherited disorder in which the patient has mutations in the genes encoding enzymes of thyroid hormone synthesis Causes impaired T3/T4 synthesis and decreased circulation => chronic TSH secretion by AP => hyperplasia of thyroid gland

Subclinical Hypothyroidism

A term used to describe asymptomatic patients who are clinically euthyroid, with thyroid hormone levels at the lower end of the reference range/normal, but with raised serum TSH If asymptomatic, don't treat If symptomatic, treat the same way you'd treat hypothyroidism (levothyroxine)

A 33-year-old woman delivered a baby three months ago. She now presents with a small, firm swelling in her thyroid region. There is no pain. She states: "I didn't realize I would lose this much weight from breastfeeding." Her thyroid-stimulating hormone and immunoglobulin levels are low. Which one of the following would be the most appropriate next step? A. Cautious initiation of treatment with beta blockers. B. Thyroid uptake testing and scan. C. Initiation of levothyroxine to prevent hypothyroidism. D. Initiation of treatment with thioamides. E. Treatment for Graves disease as soon as the patient stops breastfeeding.

A. Cautious initiation of treatment with beta blockers. Dx: Painless postpartum thyroiditis Approximately 5 to 7 percent of women who give birth develop postpartum thyroiditis, probably as a result of an autoimmune process. Approximately one half of these patients have a family history of autoimmune thyroid disease, and there is an association with human leukocyte antigens HLA-DRB, -DR4, and -DR5, as in Hashimoto's disease.16 Most patients present with a painless, small, nontender, firm goiter within two to six months after delivery. Hypothyroidism occurs in 43 percent of patients before the recovery phase, hyperthyroidism in 32 percent, and hyperthyroidism followed by hypothyroidism in 25 percent. About one third of patients with the hyperthyroid variant have asymptomatic hyperthyroidism. Hyperthyroidism usually occurs two to 10 months after delivery, most commonly at three months, with recovery taking place over the next two to three months. Hypothyroidism occurs between two and 12 months after delivery, most commonly at six months. Most patients (80 percent) have normal thyroid function at one year. However, 30 to 50 percent of patients develop permanent hypothyroidism within nine years.16,17 Elevated levels of antithyroid peroxidase antibodies are found in 80 percent of patients, but the erythrocyte sedimentation rate typically is normal. It is important to distinguish painless postpartum thyroiditis from Graves' disease occurring in the postpartum period. The presence of an audible bruit over the gland, exophthalmos, hypervascularity with increased blood flow seen on Doppler ultrasonography, thyroid-stimulating immunoglobulins in the serum, and a high RAIU are characteristic of Graves' disease but not of postpartum thyroiditis.Thyroid uptake and scan should not be performed in women who are breastfeeding. Treatment of hyperthyroidism involves symptom relief with beta blockers, although caution is necessary in breastfeeding mothers because beta blockers are secreted into breast milk. Thioamides are not useful because the cause of hyperthyroidism is the release of preformed hormone secondary to destruction of the gland. For symptomatic hypothyroidism, levothyroxine may be initiated; treatment may be tapered and stopped after six to nine months. Women with euthyroidism who have antithyroid peroxidase antibodies have a 25 percent risk of developing postpartum thyroiditis; therefore, susceptible pregnant women-those with type 1 diabetes, a history of postpartum depression, or a strong family history of autoimmune thyroid disease-should be screened for antithyroid peroxidase antibodies. Patients with postpartum thyroiditis who have antithyroid peroxidase antibodies have a 70 percent risk of recurrence following a subsequent pregnancy.18

Hurthle cells of Hashimoto Thyroiditis

AKA Askanazy Cells Hurthle cells are derived from the follicular epithelial cells and characterized by having a eosinophilic granular cytoplasm. In Hashimoto Thyroiditis, Hurthle cells line the atrophic follicles Because thyroid follicles are normally lined by low cuboidal epithelium, this is also known as Hürthle cell metaplasia. Hurthle cells can also be seen in a variant of follicular thyroid cancer called Hürthle cell carcinoma

Phases of Subacute Granulomatous Thyroiditis

Acute phase - Lasts 3-6 weeks and presents primarily with pain; symptoms of hyperthyroidism also may be present Transient asymptomatic and euthyroid phase - Lasts 1-3 weeks Hypothyroid phase - Lasts from weeks to months; it may become permanent in 5-15% of patients Recovery phase - Characterized by normalization of thyroid structure and function Usually unfolds over a period of 3-6 months Just like Hashimoto's, first you have a hyperthyroid phase, then hypothyroid

Which drugs are associated with Hypothyroidism?

Amiodarone Lithium Sulfonamide

A 46-year-old male presents with heat intolerance, increased appetite, diarrhea, and weight loss. He is a non-smoker and non-alcoholic. He has a history of paroxysmal atrial fibrillation and has been on coumadin and amiodarone. His vital signs: BP is 130/80 mm Hg; PR is 90/min; RR is 16/min and is afebrile. On examination, there is a non-tender swelling on the front of his neck that moves with swallowing. On eye examination, there is no exophthalmos, ophthalmoplegia, lid lag or chemosis. Examination of lungs and heart is normal. Labs show elevated total T3 and T4, low TSH, decreased radioiodine uptake and increased serum thyroglobulin levels. Based on these findings, what is the most likely diagnosis? A. Grave''s disease B. Subacute lymphocytic thyroiditis C. Subacute granulomatous thyroiditis D. Factitious hyperthyroidism E. Euthyroid sick syndrome

B. Subacute lymphocytic thyroiditis The above patient has clinical and laboratory evidence of hyperthyroidism (increased T3 and T4 and low TSH). Grave's disease is unlikely in the above patient because of the absence of eye signs and low radioiodine uptake. In Grave's disease, there is increased de novo synthesis of thyroid hormones and as a result there is increased radioiodine uptake. Patients with thyroiditis have inflammation of their gland with the result of decreased de novo synthesis and release of preformed hormone from the gland. Radioactive iodine uptake is low in such patients and serum thyroglobulins are high. These patients usually have transient hyperthyroidism, followed by hypothyroidism followed by recovery. Subacute lymphocytic thyroiditis is painless and there is mild diffuse enlargement of the gland. Postpartum thyroiditis is very similar to subacute lymphocytic thyroiditis. Subacute lymphocytic thyroiditis (painless thyroiditis) should be suspected in any women, or men who develops features of hyperthyroidism of less than 2 months duration and has small painless goiter. This is frequently occurs in patients who are receiving amiodarone, interferon alfa (for hepatitis-C) or interleukin-2. Subacute granulomatous thyroiditis is very painful and it is viral in origin. Subacute granulomatous thyroiditis is also called DeQuervains, postviral or subacute thyroiditis. Patients with factitious hyperthyroidism have no thyroid enlargement, low radioiodine uptake and low serum thyroglobulin levels.

Which one of the following is a characteristic of postpartum thyroiditis? A: Thyroid storm is a common complication. B: Often there are usually 2 phases (hyperthyroid and hypothyroid.) C: Aggressive thyroid ablation rapidly improves symptoms. D: Usually associated with prenatal hypothyroidism E: Unlikely to recur with future pregnancies.

B: Often there are usually 2 phases (hyperthyroid and hypothyroid.)

A 31-year-old female comes for follow-up three months after an uneventful pregnancy. She complains of palpitations, shortness of breath, sweating, heat intolerance, and weight loss. On examination she appears to be thyrotoxic. Her labs show: TSH: 0.01 mU/ml (normal 0.35 - 5.0 mU/ml) T4: 18 mg/dl (normal 4 - 11 mg/dl) T3: 210 ng/dl (normal 80 - 180 ng/dl) Her radioactive iodine uptake in the thyroid gland is 1.5% at 24 hours. The anti-TPO antibody level is elevated at 23 IU/ml (normal less than 2 IU/ml). What is the most likely diagnosis of her thyroid dysfunction? A) Graves' disease B) Hashimoto's thyroiditis C) Postpartum thyroiditis D) Subacute thyroiditis E) These values are normal during the postpartum period

C) Postpartum thyroiditis The patient has a classical presentation of postpartum thyroiditis. This condition is common in the postpartum period, is caused by autoimmunity, and has a triphasic course. It starts as a thyrotoxicosis a few weeks after delivery, with a characteristic low, radioactive iodine uptake (1st phase). This thyrotoxic phase is then followed by a hypothyroid phase (2nd phase) lasting up to a few months. About 80% of patients finally recover (3rd phase) compared to nearly 100% recovery in subacute thyroiditis. Permanent hypothyroidism develops in about 20% of patients. (Choice A) Radioactive iodine uptake is increased in Graves" disease. (Choice B) Hashimoto's thyroiditis usually presents with goiter and hypothyroidism, and the titer of anti-TPO antibodies is higher. (Choice D) The thyroid gland is extremely tender in subacute thyroiditis. (Choice E) During pregnancy, T4 and T3 are elevated due to increased levels of thyroid binding globulin induced by estrogens. In the postpartum period, T4 and T3 levels return to normal. Free thyroid hormones (Free T3 and free T4) and TSH remain within normal range during pregnancy and the postpartum period.

A 45-year-old woman with a history of thyroid disease presents to her physician with an anterior neck mass. Biopsy demonstrates non-Hodgkin's lymphoma. Which of the following thyroid conditions most likely preceded the development of lymphoma in this patient? A. Follicular thyroid carcinoma B. Graves disease C. Hashimoto's thyroiditis D. Nodular goiter E. Papillary thyroid carcinoma

C. Hashimoto's thyroiditis

A thyroid specimen reveals marked lymphocytic infiltration and scattered lymphoid follicles with germinal centers on histological examination. Follicular cells exhibit oxyphilic change, with numerous Hurthle cells. Which of the following is the mechanism accounting for this condition? A) Type 1 Hypersensitivity B) Type 2 Hypersensitivity C) Type 3 Hypersensitivity D) Type 4 Hypersensitivity

D) Type 4 Hypersensitivity

A 45-year-old woman presents to her physician because of a severe "sore throat." Physical examination demonstrates fever and an extremely tender, enlarged thyroid gland, but no throat erythema. Serum thyroid studies demonstrate a mild degree of hyperthyroidism. Two months later, the patient is asymptomatic, and thyroid function tests have returned to normal. She never again experiences difficulty with her thyroid function. Which of the following was the most likely cause of her hyperthyroidism? A. Diffuse nontoxic goiter B. Grave's disease C. Hashimoto's thyroiditis D. Subacute granulomatous thyroiditis E. Subacute lymphocytic thyroiditis

D. Subacute granulomatous thyroiditis This patient most likely has subacute granulomatous (de Quervain's) thyroiditis, which frequently develops after a viral infection. Microscopically, it is characterized by microabscess formation within the thyroid, eventually progressing to granulomatous inflammation with multinucleated giant cells. Clinically, patients may experience fever, sudden painful enlargement of the thyroid, and/or symptoms of transient hyperthyroidism. The disease usually abates within 6 to 8 weeks. Diffuse nontoxic goiter (choice A) by definition does not produce hyperthyroidism. The hyperthyroidism of Graves disease (choice B) does not spontaneously remit. Hashimoto's thyroiditis (choice C) can cause transient hyperthyroidism, but then goes on to cause hypothyroidism. Subacute lymphocytic thyroiditis (choice E) can cause transient hyperthyroidism, but is characteristically painless

Why is hyperthyroidism seen early in Hashimoto Thyroiditis?

Damage of thyroid follicles => leaking out of thyroid hormone => initial hyperthyroidism Eventual destruction of follicles => hypothyroidism

What is the most common cause of cretinism in the developed world? What is the most common cause of cretinism in the developing world?

Developed: Thyroid dysgenesis Developing: Iodine Deficiency

An endocrinologist examines a patient suspected of having Riedel thyroiditis. Which of the following findings on physical examination would best help confirm the diagnosis? A. Eyeball protrusion B. Massive soft thyroid gland C. Single large thyroid nodule D. Very tender and painful thyroid E. "Woody" thyroid gland

E. "Woody" thyroid gland

Which is more severe to the fetus, maternal thyroid deficiency early or late in pregnancy?

Early in pregnancy For the first 10-12 weeks of pregnancy, the baby is completely dependent on the mother for the production of thyroid hormone. By the end of the first trimester, the baby's thyroid begins to produce thyroid hormone on its own. If there is maternal thyroid deficiency before the development of the fetal thyroid gland, mental retardation is severe. In contrast, maternal thyroid hormone deficiency later in pregnancy, after the fetal thyroid has become functional, does not affect normal brain development

Thyroid hormone is essential in the fetal period for normal maturation of the CNS T/F?

F! In the fetal period, low thyroid levels may still cause normal growth rates but thyroid hormone is essential in the PERINATAL period and deficiencies cause irreversible changes leading to mental retardation The most critical period for the effect of thyroid hormone on brain development is the first few months of life

Grave's disease is distinct from Hashimoto's Thyroiditis in that it has antibodies against the TSH receptor T/F?

F! Both Grave's Disease and Hashimoto Thyroiditis can have antibodies against the TSH receptor. However, in Grave's these antibodies stimulate the receptor while in Hashimoto, they block it

Why might you want to check serum Vitamin B12 levels in a patient with Hashimoto Thyroiditis?

Hashimoto Thyroiditis is frequently associated with autoimmune conditions such as pernicious anemia, which is characterized by impaired absorption of vitamin B12. Therefore checking vitamin B12 levels would not be unreasonabl

Most common cause of sporadic goiter in children in iodine sufficient areas

Hashimoto!

While both Hashimoto Thyroiditis and Subacute (de Quervain) Thyroiditis can present as both hypo and hyperthyroidism, Hashimoto Thyroiditis presents most commonly as _________ (hypo/hyper) and Subacute (de Quervain) Thyroiditis presents most commonly as _________ (hypo/hyper)

Hashimoto: Hypo de Quervain: Hyper

Hypothyroidism is most commonly caused by

Hashimotos thyroiditis (in the developed world) Iodine deficiency (in developing countries)

What is Hashitoxicosis?

Hashitoxicosis is a transient hyperthyroidism caused by inflammation associated with Hashimoto's thyroiditis disturbing the thyroid follicles, resulting in excess release of thyroid hormone. When this process is complete, hypothyroidism becomes apparent.

Delayed relaxation after testing the ankle jerk reflex is a characteristic sign of?

Hypothyroidism

Hypothyroidism and Carpal Tunnel Syndrome

Hypothyroidism may be associated with carpal tunnel syndrome because hypothyroid patients tend to retain fluid in connective tissues due to an accumulation of mucopolysaccarides, a substance that accumulates abnormally in hypothyroidism. This exacerbates the swelling and worsens the compression of the median nerve as it passes under the connective tissues overlying the wrist. When hypothyroidism is treated, the symptoms of carpal tunnel syndrome may improve. Therefore, unless there is evidence of severe nerve injury, hypothyroid patients with carpal tunnel syndrome should wait for a few months after their hypothyroidism is corrected before considering surgery to release the pressure on the median nerve.

Chromosomal Aneuploidies and Hashimoto's Thyroiditis

Incidence is increased in patients with chromosomal disorders, including Turner, Down's, and Klinefelter syndromes

2 common sites of myxedema in hypothyroidism?

Larynx => deepening of voice Tongue => enlargement

Describe the length of time of thyroid replacement therapy in Hashimoto thyroiditis

Lifelong!

Hepatic Hemangiomas and Hypothyroidism

Massive Hepatic Hemangiomas have been shown to cause acquired hypothyroidism due to production of a deiodinase which causes insufficient peripheral thyroid hormone levels

Causes of Cretinism

Maternal hypothyroidism during early pregnancy Thyroid Agenesis Thyroid Dysgenesis Dyshormonogenetic goiter Iodine Deficiency

42yo M with 3-month history of fatigue, generalized weakness, and depressed mood. Cold intolerance, muscle aches, and constpiation. Follows a strict vegetarian diet. Wife has hypothyroidism rx with levothyroxine. Dry skin, testes are small. TSH if 0.1. T4 is 2.3. Mechanism? - Deficient pituitary production of TSH

NMBE 4 step 2. find it

What is the most common location for an ectopic thyroid gland?

Nearly all (90%) of ectopic thyroid glands are found at the back of the tongue (lingual thyroid) (The thyroid begins its development at the back of the tongue and then migrates to its position below the thyroid cartilage in the neck. Failure to migrate along the thyroglossal duct may therefore result in a thyroid gland at the back of the tongue)

People with Hashimoto's are at increased risk of developing ?***************

Non-Hodgkin Lymphoma (B-Cell Malignant Lymphoma)

Is the thyroid gland painful or painless in Subacute lymphocytic thyroiditis?

Painless

9 P's of Cretinism

Pot-bellied Pale Puffy-faced child with Protruding umbilicus Protuberant tongue Poor brain development Problems Feeding Prolonged Jaundice hyPotonia EMEDICINE HAD A GOOD PIC

Primary vs Secondary Hypothyroidism

Primary will have an increase in TSH, Low T4 Secondary will have a decrease in TSH, Low T4 Secondary hypothyroidism is a decrease in thyroid hormone levels due to a decrease in production of TSH or rarely TRH

What are the four carcinomas that like to spread hematogenously?

RCC Choriocarcinoma Hepatocellular Follicular carcinoma of thyroid

What is the most effective treatment for Riedel Thyroiditis and describe the mechanism behind it

Tamoxifen Tamoxifen stimulates the release of TGF-B, which may inhibit the fibroblastic proliferation characteristic of Riedel's thyroiditis There are no estrogen receptors in Riedel tissue so the MOA is not tamoxifen's antiestrogen activity

Treatment of Hashimoto's

The treatment of choice for Hashimoto thyroiditis (or hypothyroidism from any cause) is thyroid hormone replacement. The drug of choice is orally administered levothyroxine sodium, usually for life.

What is Thyroid Dysgenesis

Thyroid dysgenesis refers to defective thyroid gland development and includes thyroid agenesis (congenital absence of a thyroid), hypoplasia (congenitally small thyroid) and ectopy (thyroid tissue in an abnormal location)

Explain the mechanism behind the symptoms of night blindness and yellowing of skin in hypothyroidism

Thyroid hormone normally drives the conversion of B-carotenes into Retinoic Acid (Vitamin A) *Hyper Beta Carotenemia => yellow/orange tint of skin *Decreased Vitamin A => night blindness

Hashimoto Thyroiditis?

Type 4 Thyroid cell death results from a failure of self-tolerance to thyroid auto-antigens: Activated CD4 (helper) T lymphocytes that are sensitized to thyroid antigens stimulate proliferation of autoreactive CD8 T cells which attack thyrocytes Activated CD4 lymphocytes may also release IFN-y to activate macrophages, which release inflammatory mediators that inflict follicle damage Although Activated CD4 cells also recruit autoreactive B cells to produce antibodies against thyroid antigens (thyroid peroxidase/microsomal, thyroglobulin, TSH receptor), they are not mediators of damage and the ADCC mechanism is unlikely

Subacute Granulomatous thyroiditis typically follows?

Viral Infection CMV, Adenovirus, Mumps usually following symptoms such as fever, myalgia, and pharyngitis

Foods which impair the absorption of levothyroxine

cholestyramine, ferrous sulfate, sucralfate, calcium carbonate, aluminum hydroxide (and other antacids), and iron-containing multivitamins

Symptoms of Hypothyroidism

constipation enlarged tongue deepening of voice **

Is pretibial myxedema found in hypo and hyperthyroidism pitting or non pitting?

nonpitting

Is the goiter of Subacute Granulomatous Thyroiditis (de Quervain) painful or painless?

painful querVAIN is associated with PAIN ****add