Study Guide Test 1

Thyroid hormone secretion is stimulated by?

Thyroid hormone secretion is stimulated by?

primarily controlled by the thyroid-
stimulating hormone (TSH) produced by the pituitary gland

Common sonographic findings with adenoma

1. commonly have peripheral ‘halo’

2. ‘eggshell’ calcification (posterior shadowing)

3. complex cyst

PTH target hormones

1. Bone
2. Kidney
3. Intestine to enhance calcium absorption

Salivary gland anatomy

Hormones secreted by thyroid

1. thyroxine (T4)
2. triiodothyronine (T3)
3. calcitonin (thyrocalcitonin

malignant sonographic characteristics

solid, hyperechoic

Calcifications

Most common thyroid abnormalities / inflammations

Nodular Thyroid Disease

Graves disease

autoimmune caused by antibodies that continuously activate TSH receptors.

underlying cause of hyperthyroidism in 50-80% of cases

Hyperparathyroidism lab tests

-↑ PTH -↑ Calcium -↑ Alk Phos

Parathyroid Adenoma lab test

-↑ Calcium -↓ Phosphate

Hypothyroidism

Decreased activity of the thyroid gland

associated with infertility

Benign sonographic characteristics

hypoechoic

Thyroid Sonography

hyperechoic

homogenous

Hypothyroidism causes T3, T4, and TSH to do what?

1. T3 and T4 = LOW

2. TSH = HIGH

Hyperthyroidism causes T3, T4, and TSH to do what?

1. T3 and T4 = HIGH

2. TSH = LOW

Hypothyroidism

most common

Decreased activity of the thyroid gland

associated with infertility

Primary Hypothyroidism

1. Most common

2. Caused by

   1. Defective hormone synthesis

   2. iodine deficiency

Secondary Hypothyroidism

1. Less common

2. Caused by

   1. Pituitary adenoma

Signs of Hypothyroidism

1. Myxedema (thickening and swelling of skin)

2. Weight gain

3. Hair loss

4. Increased subcutaneous tissue around eyes

Hyperthyroidism

Hyperactivity of thyroid gland

Dramatically increases metabolic rate

Primary Hyperthyroidism

Excess thyroid hormone that is synthesized and secreted by thyroid gland itself

Secondary Hyperthyroidism

1. Rare

2. pituitary adenoma

Signs of Hyperthyroidism

1. Nervousness

2. Weight loss

3. Increased appetite/constant hunger

4. Exophthalmos (protruding eyes)

Hypothyroidism Causes

1. Low intake of iodine (food)

2. Inability to produce thyroid hormone

3. Masses on pituitary gland

TSH lab values

3-30 ng/mL

T4 lab values

free 0.8-2.4 ng/dL

total 4-11 ng/mL

T3 Lab values

75-220 ng/mL

Calcitonin Lab values

<100 pg/mL

subacute thyroiditis

viral infection that causes diffuse inflammation

brachial cleft cyst

remnant of embryonic development that appears as a cyst in the lateral neck

parathyroid adenoma

small, solid, oval

homogenous

hypoechoic

produces TSH

pituitary gland

parathyroid gland function

maintain homeostasis of blood calcium concentration

brachial cleft cyst

superficial cystic structure lying directly below the angle of the mandible

adenoma

benign solid tumor

normally solitary

adenopathy

enlargement of glands

cold nodule

area seen on nuclear medicine study as a region of thyroid where the radioisotope has not been taken up

euthyroid

thyroid producing the right amount of hormone

goiter

focal or diffuse thyroid gland enlargement due to iodine deficiency

hashimoto’s thyroiditis

most common inflammatory disease of the thyroid

heterotopic

occuring in abnormal place or wrong part of body

hyperparathyroidism

disorder associated with elevated serum calcium levels, usually caused by benign parathyroid adenoma

indolent

little pain

slow growing

microcalcifications

hyperechoic foci that may or may not shadow

papillary carcinoma

most common form of thyroid cancer

ages 20-30

hypoechoic, microcalcification

parathyroid hormone

regulates serum calcium and phosphorus

primary hyperparathyroidism

over secretion of parathyroid hormone

thyroglossal duct

congenital anomaly located anterior to trachea, extending from base of tongue to isthmus of thyroid

follicular carcinoma

irregular margins

thick irregular ‘halo’

nodular enlargement

(must use histology NOT FNA)

medullary carcinoma

hypoechoic solid mass

multiple

anaplastic carcinoma

large, solid, hypoechoic

aggressive, can compress local structures of the neck

rare, <10 % survive after 5 years, no effective therapy

secondary hyperparathyroidism

vit D deficiency or

chronic renal failure

parathyroid cyst

Sonographically CANNOT be differentiated from other cystic neck masses

parathyroid carcinoma

malignant

associated with primary hyperparathyroidism

↑ PTH ↑ Calcium

thyroglossal duct cyst

most common

oval

midline of neck anterior to trachea, superior to isthmus

thyroid adenoma

nodules contained in fibrous capsule

nontoxic goiter

without evidence of discrete nodulant and without functional disturbance

most common cause of primary hypothyroidism

hashimotos

definitive diagnosis of papillary carcinoma

FNA

parathyroid gland location

2 superior, posterior to mid portion of thyroid

2 inferior,, posterior to lower thyroid

most common cause of hyperparathyroidism

parathyroid adenoma

most common cause of primary hyperparathyroidism

parathyroid adenoma

most common sonographic appearance of thyroid carcinoma

hypoechoic

subacute thyroiditis

causes diffuse inflammation

pleomorphic adenoma

most common benign salivary tumor

parotidectomy recommended

Warthin’s tumor

2nd most common benign salivary tumor

parathyroid adenoma

↑ serum Calcium ↓ Alk Phos ↓Vit D

multiple small echogenic foci with posterior shadowing bilaterally

Signs of Papillary Carcinoma

firm right lateral neck swelling

unexplained weight loss

no diet