HDS Renal/Endo Week 3 Pathology

Hypo/Hypercalcemia, Hypo/Hyperthyroidism, Parathyroid, Thyroid

The thyroid is composed of two lateral lobes connected by a thin ____, usually located below and anterior to the larynx

isthmus

A partially involuted thyroglossal duct may present as a ____ on the thyroid

pyramidal lobe

The ____ (of the tongue) is the remnant of the thyroglossal duct

foramen cecum

What is the most common site for ectopic thyroid tissue?

base of the tongue

If ectopic thyroids are removed, what is a potential adverse effect?

hypothyroidism

What is the most common cause of hypothyroidism in regions where iodine levels are adequate?

Hashimoto thyroiditis

Hashimoto thyroiditis is histologically associated with chronic inflammation with ____

germinal centers

Histologically, Hashimoto thyroiditis may have ____, which are eosinophilic metaplastic cells that line the follicles

Hurthle cells

Patients with Hashimoto thyroiditis have an increased risk for ____; presents as an enlarging thyroid late in disease course

B-cell (marginal zone) lymphoma

Hashimoto thyroiditis is more common in which gender?

female

The thyroid will be ____ in Hashiomoto thyroiditis

nontender

Initially, Hashimoto thyroiditis presents as ____ due to thyrotoxicosis during follicular rupture

hyperthyroidism

Subacute granulomatous thyroiditis (de Quervain) is a self-limited disease often following ____

viral infection

Does subacute granulomatous thyroiditis (de Quervain) present with a tender or nontender thyroid?

tender

Subacute granulomatous thyroiditis (de Quervain) may initially present with ____, which is then followed by ____

hyperthyroidism; hypothyroidism

What histological findings are associated with subacute thyroiditis (de Quervain)?

granulomatous inflammation

The most common cause of hyperthyroidism is ____

Graves disease

Graves disease is associated with ____ which occurs due to activation of retro-orbital ____

exophthalmos; fibroblasts

Graves disease is associated with ____ which occurs due to activation of dermal ____

pretibial myxedema; fibroblasts

____ is a characteristic histological finding associated with Graves disease

Scalloped colloid

What demographic is most commonly associated with Graves disease?

women of childbearing age (often presents during stress)

What HLA subtypes are associated with Graves disease?

B8, DR3

What type of hypersensitivity is Graves disease?

type II (antibody-mediated)

Which thyroid disorder is associated with high concentrations of thyroid-stimulating immunoglobulins?

Graves disease

What type of goiter is associated with Graves disease?

diffuse goiter

Lid lag in Graves disease is caused by increased ____ stimulation of the ____ muscle

sympathetic; superior tarsal

What are the levels of TSH in hyperthyroidism due to Graves disease or thyroid neoplasm? Why?

decreased, due to negative feedback from increased level of free T3

Hyperthyroidism may be treated surgically via ____

thyroidectomy

Thyroid-stimulating hormone (TSH) has a trophic effect on the thyroid gland, thus, chronic elevation of TSH causes ____ of the thyroid gland

hypertrophy/hyperplasia

How does iodine deficiency cause formation of a goiter?

constant elevation of TSH

Iodine deficiency results in ____ levels of TSH

increased

What is the term for a substance that inhibits thyroid hormone production?

goitrogen

Dyshormonogenetic goiter (congenital defect in thyroid hormone production) most commonly involves a ____ deficiency

thyroid peroxidase

One cause of cretinism is ____, which is due to a congenital defect in thyroid hormone production

dyshormonogenetic goiter

____ is an enlarged thyroid gland with multiple nodules

Multinodular goiter

A ____ multinodular goiter occurs when a multinodular goiter has hyperfunctioning follicular cells that work independently of TSH, causing increased release of T3 and T4

toxic

Toxic multinodular goiter is most often due to ____ mutations (60% of cases)

TSH receptor

Thyroid adenoma, cancer, and cysts all may cause which type of goiter?

nodular

If a thyroid nodule has decreased uptake of 131I, it is considered a “____” nodule

cold

If a thyroid nodule has increased uptake of 131I, it is considered a “____” nodule; seen in Graves disease or nodular goiter

hot

A single "____" nodule in the thyroid indicates a possible cancer

cold

Thyroid nodules are more likely to be ____

benign

Thyroid nodules may be studied using ____ radioactive uptake studies

131I

How is a biopsy performed for a thyroid nodule?

fine needle aspiration (FNA)

The most common type of thyroid adenoma is ____ adenoma

follicular

What is the main distinguishing feature between follicular adenoma and follicular carcinoma of the thyroid?

follicular adenoma has a lack of capsular and vascular invasion

Thyroid follicular adenoma is a benign tumor of follicles surrounded by a ____

fibrous capsule

What is the most common type of thyroid carcinoma?

papillary carcinoma (80%)

Exposure to ionizing radiation in childhood is a major risk factor for ____

thyroid papillary carcinoma

Thyroid papillary carcinoma may be lined by cells with clear, “____” nuclei

Orphan Annie eye

In addition to 'Orphan Annie eye' nuclei, thyroid papillary carcinoma may have cells with nuclear ____

grooves

Thyroid papillary carcinoma may have ____ bodies on biopsy, which are characterized by concentric layers of calcification

psamomma

Thyroid papillary carcinoma often spreads to the ____ (lymphatic invasion)

cervical nodes

What is the prognosis of thyroid papillary carcinoma?

excellent

Thyroid follicular carcinoma is characterized by a malignant proliferation of follicles surrounded by a ____ with ____

fibrous capsule; invasion through the capsule

Can fine needle aspiration distinguish between thyroid follicular adenoma versus carcinoma?

no, the fibrous capsule cannot be visualized with FNA

____ is a malignant proliferation of parafollicular "C" cells

Thyroid medullary carcinoma

Thyroid medullary carcinomas secrete ____

calcitonin

In thyroid medullary carcinoma, calcitonin often deposits within the tumor as ____, which may be visualized with a ____ stain

amyloid; Congo red

Detection of a RET oncogene mutation warrants prophylactic ____

thyroidectomy

What type of thyroid carcinoma is illustrated in this histology slide?

medullary carcinoma

What two multiple endocrine neoplasias are associated with thyroid medullary carcinoma?

MEN 2A and 2B

____ is an undifferentiated malignant tumor of thyroid

Thyroid anaplastic carcinoma

What demographic is most commonly associated with anaplastic carcinoma?

elderly women

Thyroid ____ carcinoma often invades local structures leading to dysphagia or respiratory compromise

anaplastic

What is the prognosis of thyroid anaplastic carcinoma?

poor

Medullary carcinoma of the thyroid is characterized by deposition of ____ within the tumor

calcitonin

How does iodine enter the follicular epithelial cell (as part of thyroid hormone synthesis)?

through Na+-I- cotransport (iodine pump)

Once I- has been pumped into the cell for thyroid hormone synthesis, it is ____ to I2 by the enzyme ____ in the follicular cell membrane

oxidized; thyroid peroxidase

The ____ of I2 into thyroglobulin is mediated by the enzyme ____

organification; thyroid peroxidase

After organification of I2, coupling between a molecule of ____ and a molecule of ____ may combine to form ____

MIT; DIT; triiodothyronine (T3)

After organification of I2, coupling between two molecules of ____ may combine to form ____

DIT; thyroxine (T4)

After release from iodinated thyroglobulin, T4 and T3 enter the ____

systemic circulation

Once T3 is produced inside its target cell, it enters the ____ and binds to a ____ receptor

nucleus; nuclear

Thyroid-stimulating hormone (TSH) secretion is decreased in response to ____

free T3/T4

What is the main thyroid hormone (T3 or T4) that is secreted?

T4

Once in target tissues, the enzyme ____ converts ____ to ____ by removing one atom of I2

5’-deiodinase; T4; T3

In the circulation, most of the T3 and T4 is bound to ____

thyroxine-binding globulin (TBG)

The T3 resin uptake test may be used to indirectly assess circulating levels of ____

TBG

What is the result of hepatic failure on a T3 resin uptake test?

resin uptake is increased

What is the result of pregnancy on a T3 resin uptake test?

resin uptake is decreased

Which three antibodies are associated with Hashimoto thyroiditis?

anti-thyroid peroxidase, anti-thyroglobulin, anti-microsomal

____ is a cystic teratoma composed primarily of thyroid tissue and thus may cause ____

Struma ovarii; hyperthyroidism

Hydatidiform moles can cause ____

hyperthyroidism

Which thyroid imbalance presents with proximal muscle weakness and increased creatinine kinase?

hypothyroidism

Does hypothyroidism present with hypo- or hyper-cholesterolemia? Why?

hypercholesterolemia due to decreased LDL receptor expression

Hypothyroidism in the perinatal period causes irreversible ____

mental retardation (cretinism)

What endocrine pathology is a reversible cause of dementia?

hypothyroidism

Which thyroid imbalance presents with decreased heat production (cold intolerance)?

hypothyroidism

Which thyroid imbalance presents with bradycardia and dyspnea on exertion?

hypothyroidism

Which thyroid imbalance presents with constipation?

hypothyroidism

In adulthood, which thyroid disorder is associated with listlessness, slowed speech, somnolence, impaired memory, and decreased mental capacity?

hypothyroidism

Which thyroid imbalance is associated with dry, cool skin and coarse, brittle hair?

hypothyroidism

Which thyroid imbalance presents with weight gain and decreased appetite?

hypothyroidism

Which thyroid imbalance presents with decreased reflexes?

hypothyroidism

Hypothyroidism causes what electrolyte imbalance?

hyponatremia

In which disorder (hyper- or hypothyroidism) may a patient present with a goiter?

both

Which thyroid imbalance is associated with warm, moist skin and fine hair?

hyperthyroidism

Which thyroid imbalance presents with increased heat production (heat intolerance)?

hyperthyroidism

Which thyroid imbalance presents with tachycardia, palpitations, and arrhythmias?

hyperthyroidism