1. Diseases of thyroid & parathyroid glands (1 of 2)
Ali Al Khader, M.D.
Faculty of Medicine
Al-Balqa’ Applied University

2. Thyroid diseases Thyrotoxicosis Hypothyroidism Thyroiditis
Graves disease
Goiters
Neoplasms
adenoma
Chronic Lymphocytic (Hashimoto) Thyroiditis
carcinoma
Subacute Granulomatous
(de Quervain) Thyroiditis
Riedel thyroiditis
Hyperfunctioning (toxic)
Subacute Lymphocytic Thyroiditis
Nontoxic

3. Thyrotoxicosis
*A hypermetabolic state due to increased T3 & thyroxine (T4) in the blood
Increased production from thyroid gland (hyperthyroidism) Exogenous Release of preformed hormones from destroyed gland
in thyroiditis
The most common cause of thyrotoxicosis
Primary
Secondary (central)
…rare
…from TSH-secreting
pituitary adenoma
Toxic
(hyperfunctional)
multinodular
goiter
1- Granulomatous (de Quervain) thyroiditis (painful)
2- Subacute lymphocytic thyroiditis (painless)
*Thyrotoxicosis also can occur in Hashimoto thyroiditis
(Hashitoxicosis)
Graves
Disease
…the most
common cause
of hyperthyroidism
Toxic
(hyperfunctional)
adenoma

4. Clinical manifestations of thyrotoxicosis
Soft, warm & flushed skin…due to peripheral vasodilation to increase heat loss
Heat 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 irritability
Proximal 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

5. *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
Clinical scenarios
The thyroid function test (TFT)
Low T4 and high TSH = 1ry hypothyroidism
Normal T4 and high TSH = subclinical 1ry hypothyroidism
Low 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
If we want to choose 1 test,
TSH is the best

6. Approach to thyrotoxicosis patient
Thyroid scan is different from thyroid uptake
In 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
The examples and scenarios mentioned here are not all examples,
but they are enough at this level
*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)
Thyrotoxicosis with high 24-h RAI uptake
Thyrotoxicosis with low 24-h RAI uptake
Graves disease
Factitious
Multinodular goiter
Subacute (painless) thyroiditis
Toxic adenoma
Granulomatous (painful) thyroiditis
Secretion from struma ovarii (ovarian teratoma containing mostly thyroid tissue)
Iodine-induced hyperthyroidism
RAI: Radioactive iodine
Like using iodinated contrasts for imaging

7. Hypothyroidism This label means: can cause enlargement (goiter) =
Goitrous hypothyroidism
Secondary (pituitary or
hypothalamic failure)
…rare
Primary
Iatrogenic
Autoimmune
Congenital
Hashimoto thyroiditis
Ablation
As a side
effect
Genetic
The most common
cause in countries
where iodine is
supplemented in
dietary salt products
Surgical ablation
-lithium
-iodides
-p-aminosalicylic
acid
Dyshormonogenetic goiter
(problem in thyroid
hormone production)
Thyroid dysgenesis
(problem in thyroid
tissue development)
Ablation by radioiodine therapy
Ablation by external radiation
Endemic deficiency
of dietary iodine
rare but the most common cause of
congenital hypothyroidism in the U.S.
a common cause of hypothyroidism
in infants and children worldwide

8. Clinical manifestations of hypothyroidism
Cretinism in infancy or early childhood and myxedema in older children and adults
*Glycosaminoglycans with associated water are the cause of myxedematous
fluid accumulation

9. The manifestations range from
Thyroiditis
Chronic Lymphocytic
(Hashimoto) Thyroiditis
Subacute Granulomatous
(de Quervain) Thyroiditis
Subacute Lymphocytic
(Painless) Thyroiditis
Riedel Thyroiditis
-extensive fibrosis involving the thyroid and contiguous neck structures
-an IgG4-related disease
-mainly 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
years
-Females more
-Viral infection-induced
…not autoimmune
-A majority of patients have a
history of an upper-respiratory
infection shortly before the
onset of thyroiditis
-painful
-usually self-limited
-destroyed follicles, extravasated
colloid with exuberant granulomatous reaction
-Sometimes after delivery
(postpartum thyroiditis)
-Autoimmune (antithyroid antibodies in majority of patients)
-middle-aged women
-usually self-limited
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

10. Graves disease
Diffuse goiter + thyrotoxicosis + (in 40%) infiltrative ophthalmopathy (exophthalmos)
+ (in a minority of patients) infiltrative dermopathy (pretibial myxedema)
Pseudopapillae (no fibrovascular cores)
*20-40 years
*Women more
*1.5% to 2% of women in the
United 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
Lymphocytic infiltrate with
germinal centers is common
…not shown
Hypertrophy & hyperplasia of follicular epithelial cells

11. Goiter
Regarding 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”)

12. Thank You