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Chapter 20Endocrine Disease

Physical Signs of Endocrinopathy

1) Weakness (most frequent complaint).With weight loss : adrenal insufficiency, hyperthyroidism, and diabetes mellitus

Without weight loss -hypothyroidism, hypopituitarism, hyperparathyroidism, hyper-aldosteronism.

2) Menstrual irregularities- hypothyroidism, adrenogenital syndrome, and ovarianneoplasm.

3) Hirsutism- adrenal dysfunction

4) Loss of hair- Cushing, hypothyroidism, and hypopituitarism

5) Loss of libido- usually associate with anterior pituitary disease. Also seen in diabetesmellitus.

6) Obesity- diabetes mellitus, hypothyroidism, hypopituitarism, and Cushing.

7) Gynecomastia - adrenal tumors

8) Hypertension - hyperaldosteronism, hyperparathyroidism, pheochromocytoma

9) Polyuria & polydipsia- diabetes mellitus

Disease States: Endocrine disease can be broadly classified as-

hyperfunction

hypofunction

neoplasia- micro (3mm)

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I(a) ANTERIOR PITUITARY:

Hyperfunction - Most common causes are tumors (prolactinoma most common 20-30%)

Growth Hormoneproducing tumors are the second most common hormone producing tumor

that results in pituitary hyperfunction. In adults it is seen as acromegaly(growth only occurs

where growth centers remain - jaw, finger and toe joints. In children, whe re growth centers ar e

still active, increased growth hormone causes Gigantism.

Increased activity of the adrenal cortex ca uses hypercortisolism. Hypercortisolism is Cushings

Syndrome. There are other causes of Cushings Syndrome. When it is caused by increased

production ofACTHin the pituitary it is caused Cushings Disease.

Hypofunction-

Most cases of anterior pituitary hypofunction are due to:

--- adenomas (non-secretory)

---ischemic necrosis of the pituitaryrequires 75% destruction

---destruction of the gland by surgery or radiation

Clinical manifestations of ant pituitary hypofnctn depends on the specific hormones lacking:

-- In children: dwarfism(pituitary dwarfs differ from achondroplastic dwarfs)

-- In adults: decreased prolactin--- lactation failure

Decreased ACTH--- hypoadrenalism

Decreased TSH---- hypothyroidism

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I (b): POSTERIOR PITUITARY:

Axon terminals in the ne urohypophysis store two hor mones:ADH and oxy tocin.

As a practical matte r, only decreased ADH production cause s clinical problems--

Diabetes insipidus- lack of ADH, frequent urination, dehydration.

II. THYROID Gland Disease: see table 20-2

1.Hyperthyroid - thyrotoxicosis. A hypermetabolic state with increased stimulation of

the sympathetic system. Diagnosed by measuring serum TSH(!) and T4(^) levels. Most

associated with autoimmune diseases.

Signs:heat intolerance, muscle weakness, ocular protrusion, tachycardia.

The most notable hyper thyroid state is Graves Disease.

Gravesdisease - triad of a) thyrotoxicosis (100%), b) exophthalmia

(40%), and c) myxedema (~20%) - (pretibial classic). 20-40 years of age and

females 7X > males.

Etiology- autoimmune disorder (but not to one specific antigen).

Predominately caused by antibodies binding the TSH receptor and turning on

adenylate cyclase (kicks hormone production into high gear). Cause of

exophthalmia is not clear.

Testing- Elevated T3and T4levels AND depressed TSH.

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2.Hypothyroid - 4 types: caused by anything that interferes with thyroid hormone prod.

1) Developmental- (congenital - cretinism),

In older children and adults the condition is called myexedema.

2) Goiter- enlargement of the thyroid gland. Impaired thyroid hormone production.

The most common thyroid disease. Typically, in the USA, goiter is sporadicand for unknown reasons.

Endemic goiter- lack of iodine in diet due to environmental factors

Nodular & multinodular goiters- asymmetrical, irregular enlargement. Persons

with nodular goiters ma y be euthyroid.

3) Thyroiditis- Inflammation. Many causes- most common is Hashimoto thyroiditis.

Hashimoto- Most common thyroiditis. Autoimmune disease at the other end of the

spectrum from Graves disease---- most common cause of hypothyroidism. B-cells

produce antibodies that block the action of TSH. 45-65 years of age. Females 10-

20 times more frequently. Diffuse, symmetrical enlargement. May start with

thyrotoxicosis. Increased risk of B cell lymphomas (remember most lymphomas

are B cell type).

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4) Thyroid Neoplasia -

Benign Adenomas- Most follicular, usually solitary, most are cold. Adenomas

rarely undergo malignant transformation. Males>females, younger>older.

Malignant Uncommon in USA. Most common is papillary carcinoma.

Papillary Carcinoma- Most common malig neoplasm (~80%). predom in

females. History or thyroid irradiation increases risk. . ~80% 5 year survival rate

Medullary carcinoma represents about 5% of thyroid cancers.80% are

spontaneous; HOWEVER, the rest are assoc w/ MEN syndr (MEN II & III - AKA

IIa & IIb). Of C cell origin. 50% five year survival. They produce a variety of

hormones & symptoms are related to which hormones are produced.

III. PARATHYROID GLAND DISEASE.

Hyperfunction - Activity of the parathyroids are affected by serum calcium levels and

not a hypothalamic feedback loop.

2 forms:

Primary: usually caused by an adenoma. Causes hypercalcemia via increased

parathyroid hormone. May be sporadic or be associated with a MEN syndrome. Clinical

findings include osteoporosis, renal stones, depression and muscular weakness.

Secondary: often do to renal disease. Causes bone lesion called Brown tumor of

hyperparathyroidism.

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IV. ADRENAL CORTEX DISEASE: Disease related to hyper & hypofuction & Mass affects

A. Cortical hyperfunction Hyperfunction produces syndromes related to the

overproduction of 3 classes of hormones:

1. Increased Cortisol (Cushing Syndrome)2. Increased Mineralcorticoids (Hyperaldosteronism)3. Increased Androgens (Virilizing Syndromes)

1.Cushing syndrome: most cases caused by the administration of exogenous

adrenocortical hormones. The rest are caused as seen in Figure 20-35.

Features- hypertension, weight gain early on then moon facies, buffalo hump,

truncal obesity, weakness, cutaneous striae, osteoporosis, hirsutism, and mental

distrubances. Suppression of immune responses. Since glucocorticoids induce

gluconeogenesis, hyperglycemia and other indicators of diabetes mellitus are seen.

2. Hyperaldosteronism: Excessive levels of aldosterone causes Na retention & K+

excretion leading to hypertension. Caused by a neoplasm or cortical hyperplasia.

3. Adrenogenital Syndromes:Excess androgens caused by adrenal disorders and

gonadal disorders. Tumors are often the cause of adrenal cortical increased production

of androgens. Clinical problems include masculinization in the female and enlargement

of external genitalia and precocious puberty.

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B. Adrenal Cortical Hypofunction:As with hyper, hypofunct ion can be caused pr imarily by

adrenal disease or b/c of secondary diseases. See Table 20-8. Most important disease:

Addison disease :

Results from progressive destruction of the adrenal cortex. About 90% of cortex has to become

nonfunctional before symptoms arise. Causes

ACUTE DISEASE: sud den withdrawal of ste roid therapy.

CHRONIC DISEASE: autoimmune disease (90% of cases) and infections.

SYMPTOMS, chronic disease: progressive weakness, easy fatigability, nausea and weight

loss, hyperpigmentation, hypotension and hypoglycemia.

SYMPTOMS, acute disease: adrenal crisis, which consists of severe hypotension, shock and

coma from sudden decreases in aldosterone.

C. Adrenal Neoplasms:Adrenal cortex ma y have functional or nonf unctional adenoma s and

carcinomas. The adrenal medullais the site of the pheochromocytoma.

Pheochromocytoma - rare but these are significant because they secrete epinephrine

& norepinephrin (catecholamines are strong vasopressors - increase BP). Rule of 10s:

10% associated w/MEN syndrome, 10% malignant, 10% bilateral, & 10% extra-adrenal.

Features- HT w/associated tachycardia, headache, palpitations, tremor, diaphoresis.

Elevatedvanillylmande lic acid, a catecholamine metabolite found in the urine.

MEN SYNDROMES- MEN IIa and IIb (II and III) most significant for us as dentists.

MEN IIa (II)- Sipplesyndr. Pheochromocytoma, thyroid medullary carcinoma & primaryhyperparathyroidism.

MEN IIb (III) William syndr. Like IIa - also have neuromas of skin & mucous membr.