Diseases of thyroid & parathyroid glands - PowerPoint Presentation

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Diseases of thyroid & parathyroid glands(1 of 2)

Ali Al Khader, M.D.

Faculty of Medicine

Al-Balqa’ Applied University

Email: ali.alkhader@bau.edu.jo

Thyroid diseases

Thyrotoxicosis

Hypothyroidism

Thyroiditis

Goiters

N

eoplasms

adenoma

carcinoma

Hyperfunctioning (toxic)

Nontoxic

Chronic Lymphocytic (Hashimoto) Thyroiditis

Subacute Granulomatous

(de

Quervain

) Thyroiditis

Subacute Lymphocytic Thyroiditis

Riedel thyroiditis

Graves disease

Thyrotoxicosis Increased production from thyroid gland (

hyperthyroidism

)

Exogenous

Release of preformed hormones

from destroyed gland

i

n thyroiditis

The most common cause of thyrotoxicosis

Graves

Disease

…the most

c

ommon cause

o

f hyperthyroidism

Toxic

(hyperfunctional)

multinodular goiter

Toxic(hyperfunctional)

adenomaPrimary

Secondary (central)

…rare

…from TSH-secreting

pituitary adenoma

*A hypermetabolic state due to increased T3 &

thyroxine (T4)

in the blood

1-

Granulomatous

(de

Quervain

)

thyroiditis

(

painful

)

2-

Subacute

lymphocytic thyroiditis

(painless)

*Thyrotoxicosis also can occur in Hashimoto thyroiditis

(

Hashitoxicosis

)

Clinical manifestations of thyrotoxicosisSoft, warm & flushed skin…due to peripheral vasodilation to increase heat lossHeat intolerance and excessive sweating

Weight loss in spite of normal or even increased appetite

Rapid transit

time (hypermotility)

of the gut… diarrhea and fat malabsorption (steatorrhea)

Palpitations and tachycardia…due to increased cardiac contractility & increased tissues oxygen requirements…may cause high cardiac output heart failure

Nervousness, tremor and irritabilityProximal muscle weakness (thyroid myopathy)Ocular changes (wide, staring gaze and lid

lag)Thyroid ophthalmopathy: (wide, staring gaze and lid lag) + exophthalmos (proptosis)… in Graves disease

Apathetic hyperthyroidism…in older adults…typical thyrotoxicosis features are blunted and only present with exaggerated heart disease or weight loss

In cases of infection, surgery, cessation of

anti-thyroid medication, or any form of stress…a thyroid storm may occur

…especially in Graves…risk of fatal arrhythmia

Clinical scenariosLow T4 and high TSH = 1ry hypothyroidismNormal T4 and high TSH = subclinical 1ry hypothyroidismLow T4 and

low

TSH =

central hypothyroidism

Low T4 and

normal or mildly elevated TSH = also central hypothyroidism

High T4 and low TSH = non-central hyperthyroidism

Normal T4 and low TSH check T3 (if high: T3 thyrotoxicosis), if T3 is not high subclinical non-central hyperthyroidism

High T4 and high TSH = central hyperthyroidism

High T4 and normal or mildly decreased TSH = also central hyperthyroidism

*We

measure free T4

& free T3...these have the feedback on TSH*T3

is stronger than T4 in activating receptors…T4 is converted to T3 peripherally

*Minor change in T3/T4 will cause a large change in TSH level *Most of the time we take free T4 & TSH and analyze their levels for

the diagnosis

If we want to choose 1 test,

TSH is the best

The thyroid function test (TFT)

Approach to thyrotoxicosis patientThyroid scan is different from thyroid uptakeIn thyroid scan we use a radioactive iodine or technetium and see the distribution of its uptake in the gland…it shows if a nodule is over-uptaking (a toxic adenoma for example) or homogenous over-uptake (Graves disease for example)

In thyroid uptake, we give the iodine or technetium and just count the percentage of uptake to know if high- or low uptake

*If central hyperthyroidism, do pituitary MRI

*If non-central hyperthyroidism:

…do uptake

…if the uptake is high, do scan, it may be Graves (in scan: homogenous) or toxic adenoma (in scan: 1 spot) or toxic multinodular goiter (in scan: multiple spots)

…if the uptake is low, measure thyroglobulin, if it is high: thyroiditis (because thyroglobulin increases also with cell destruction), if it is low or normal: it may be factitious (exogenous)

The examples and scenarios mentioned here are not all examples,

but they are enough at this level

Thyrotoxicosis with high 24-h RAI uptake

Thyrotoxicosis with low 24-h RAI uptake

Graves disease

FactitiousMultinodular goiter

Subacute (painless) thyroiditisToxic adenoma

Granulomatous (painful) thyroiditisSecretion from struma

ovarii (ovarian teratoma containing mostly thyroid tissue)

Iodine-induced hyperthyroidism

RAI: Radioactive iodine

Like using iodinated contrasts for imaging

Hypothyroidism

Secondary

(pituitary or

hypothalamic failure)

…rare

Primary

Congenital

A

utoimmune

Iatrogenic

Surgical ablation

Ablation by radioiodine therapy

Ablation by external radiation

A

blation

As a side

effect

Genetic

Thyroid dysgenesis

(problem in thyroid

t

issue development)

Dyshormonogenetic

goiter

(problem in thyroid

hormone production)

rare

but

the

most common

cause of

congenital

hypothyroidism in the U.S.

Endemic deficiency

of dietary iodine

a common cause of hypothyroidism

in

infants

and children

worldwide

Hashimoto thyroiditis

The most common

cause in countries

where

iodine

is

supplemented

in

dietary

salt

products

This label means: can cause

e

nlargement (goiter) =

Goitrous

hypothyroidism

-lithium

-iodides

-p-

aminosalicylic

acid

Clinical manifestations of hypothyroidismCretinism in infancy or early childhood and myxedema

in older children and adults

*

Glycosaminoglycans

with associated water are the cause of

myxedematous

f

luid accumulation

-Protruding tongue

-Growth retardation with short limbs

-Coarse dry skin-Lack of hair and teeth-Mental deficiency

-Pot belly-Often umbilical hernia-Hypotonia

Rubin, Raphael, David S. Strayer

, and Emanuel Rubin, eds. Rubin's pathology:

clinicopathologic foundations of medicine

. Lippincott Williams & Wilkins

Thyroiditis

Chronic Lymphocytic

(

Hashimoto) Thyroiditis

-mainly 45-65 years, but any age

-Females more

-CD8, IFN-gamma, other cytokines, macrophages, anti-thyroglobulin, anti-thyroid peroxidase-Goiter with too many lymphocytes including germinal centers with destruction of follicles,

Hurthle (oxyphil) cell change and fibrosis…may end with atrophy

-CTLA-4 mutations

Subacute Granulomatous

(de

Quervain

) Thyroiditis

-30-50 years-Females more-V

iral infection-induced…not autoimmune-A majority of patients have ahistory of an upper-respiratory

infection shortly before theonset of thyroiditis-painful

-usually self-limited-destroyed follicles, extravasated colloid with exuberant granulomatous reaction

Subacute

Lymphocytic

(Painless) Thyroiditis

-Sometimes after delivery(postpartum thyroiditis)-Autoimmune (antithyroid antibodies in majority of patients)

-middle-aged women-usually self-limited

Riedel Thyroiditis-

extensive fibrosis involving the thyroid and contiguous neck structures-an IgG4-related disease

The manifestations range from

thyrotoxicosis to euthyroid state to hypothyroidism

Patients with Hashimoto thyroiditis often have other autoimmune diseases

and are at increased risk for the development of B-cell non-Hodgkin

lymphomas in thyroid

Elsevier. Kumar et al. Robbins and Cotran

pathologic basis of diseases 9

th

Graves diseaseDiffuse goiter + thyrotoxicosis

+

(in 40%)

infiltrative

ophthalmopathy (exophthalmos) + (in a minority of patients)

infiltrative dermopathy (pretibial myxedema)

*20-40 years*Women more*1.5% to 2% of women in theUnited

States…not uncommon*Genetic predisposition*HLA-DR3, CTLA-4 & PTPN22*Elevated antibodies:-TSI (thyroid-stimulating immunoglobulin)

…an IgG…specific & in all patients-Thyroid growth-stimulating immunoglobulins

-TSH-binding inhibitor immunoglobulins*Exophthalmos is caused by retroorbital

Inflammation & increased retroorbital connective tissue/glycosaminoglycans, muscle & fat

*Associated with other autoimmune diseases

Hypertrophy & hyperplasia of follicular epithelial cells

Pseudopapillae

(no

fibrovascular cores)

Lymphocytic infiltrate with germinal centers is common…not shown

Elsevier. Kumar et al. Robbins and

Cotran

pathologic basis of diseases 9

th

Elsevier. Kumar et al. Robbins basic pathology

10

th…modified

GoiterRegarding the previously mentioned goitrous diseases (other than Graves):

…Early

in

goiter

development, TSH-induced hypertrophy

and hyperplasia of thyroid follicular cells usually result in diffuse, symmetric enlargement of the gland (diffuse goiter

)…Virtually all long-standing diffuse goiters convert into multinodular goiters

Clinical manifestations:

-Cosmetic

problem of a large neck mass-It may cause airway obstruction

or dysphagia-It may cause compression of large vessels in the

neck and upper thorax (so-called “superior vena cava syndrome”)

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