thyroid pathology

goiter

broad term for an enlarged or hyperplastic thyroid gland

causes of a goiter include:

• iodine deficiency

• Graves disease

• thyroiditis

thyroid enlargement can be diagnosed by calculating:

volume measurements or by obtaining an AP thickness of the isthmus

an isthmus that measures greater than what may be indicative of thyroid enlargement?

greater than 1.0 cm

clinical findings of a goiter:

• palpable (and possibly visually) enlarged thyroid gland

• dyspnea

• dysphagia

• feeling of tightening in the throat

• coughing

• hoarseness

sonographic findings of a goiter:

• enlarged thyroid gland → isthmus that exceeds 1 cm in AP plane

• diffusely heterogenenous echotexture

• multiple nodules with cystic and solid components

multinodular goiter/adenomatous goiter

enlarged thyroid gland that contains multiple nodules with cystic and solid components

hyperthyroidism

a condition that results from the overproduction of thyroid hormones

what is the most common cause of hyperthyroidism?

Graves disease/diffuse toxic goiter

clinical findings of Graves disease:

• bulging eyes → exophthalmos

• heat intolerance

• nervousness

• weight loss → with increased appetite

• hair loss

• tachycardia, palpitations, high-output heart failure

• muscle wasting

• fine tremors

• oligomenorrhea

• pretibial myxedema

sonographic findings of Graves disease:

• enlarged gland

• heterogeneous or diffusely hypoechoic echotexture

• thyroid inferno → hypervascularity within thyroid

hypothyroidism

a condition that results from the underproduction of thyroid hormones

what is the most common cause of hypothyroidism in the US?

Hashimoto thyroiditis

Hashimoto thyroiditis/chronic autoimmune lymphocytic thyroiditis

• autoimmune disease

• the thyroid becomes inflamed, and as a result, the thyroid produces smaller amounts of thyroid hormones. In order to compensate, the pituitary gland releases more TSH, which causes the thyroid to become enlarged

clinical findings of Hashimoto thyroiditis:

• depression

• increased cold sensitivity

• elevated blood cholesterol levels

• slight weight gain may occur

• puffy face and puffiness under the eyes

• menorrhagia

• pallor

sonographic findings of Hashimoto thyroiditis:

• mild enlargement of the thyroid gland, initially

• heterogeneous echotexture

• multiple- ill-defined hypoechoic regions separated by fibrous hyperechoic tissue

• hypervascular gland

• end stage of the disease may lead to fibrosis and atrophy of the gland

what are the most common masses identified within the thyroid gland with sonography?

benign thyroid nodules

what are the types of benign thyroid nodules?

• follicular adenomas

• adenomatous/hyperplastic nodules

• colloid nodules

follicular adenomas

• most often small, round, and can have varying sonographic appearances, including completely anechoic, isoechoic, or hypoechoic

• may also have a surrounding halo

what is the most common cause of thyroid nodules?

nodular hyperplasia

hyperplastic nodules/adenomatous nodules

almost always multiple and also have varying sonographic appearances

sonographic appearance of a cystic thyroid nodule, like a colloid cyst:

a hyperechoic focus or foci may be seen, which may produce comet-tail artifact

benign characteristics of thyroid nodules include:

• extensive cystic components

• cysts < 5 mm

• hyperechoic mass

• “eggshell” calcifications

• spongiform composition

• wider-than-tall shape

• “hot” nodule → nuclear medicine finding

what is the most common form of thyroid cancer?

papillary carcinoma

what are other forms of thyroid malignancies?

• follicular carcinoma

• medullary carcinoma

• anaplastic carcinoma

• lymphoma

• metastases of the thyroid

psammoma bodies

round, calcific deposits that appear sonographically as punctate, hyperechoic foci without acoustic shadowing

malignant characteristics of thyroid nodules:

• hypoechoic mass

• taller-than-wide shape

• mass with internal microcalcifications → psammoma bodies

• solitary mass

• marked vascularity within the central part of the nodule

• interrupted peripheral calcification

• extracapsular invasion

• lobulated margins

• enlargement of the cervical lymph nodes → metastasis

• “cold” nodule → nuclear medicine finding