Hyperthyroidism Diagnostic Evaluation

Flashcards covering the diagnostic pathway, laboratory findings, and characteristic features of different forms of hyperthyroidism based on clinical guidelines.

Overt hyperthyroidism

A clinical state characterized by $\downarrow$ TSH and $\uparrow$ Total T3 and Free T4.

Subclinical hyperthyroidism

A laboratory finding characterized by $\downarrow$ TSH with normal Total T3 and Free T4 levels.

Thyrotropic adenoma

A pituitary tumor that results in $\uparrow$ or normal TSH levels alongside $\uparrow$ Total T3 and Free T4; diagnosis often involves an MRI of the pituitary gland.

$\beta\text{-hCG}$-associated hyperthyroidism

Hyperthyroidism resulting from high levels of $\beta\text{-hCG}$, which can occur in gestational thyrotoxicosis, trophoblastic tumors, hydatidiform mole, or choriocarcinoma.

Graves ophthalmopathy

A characteristic feature of Graves disease also known as exophthalmos.

Pretibial myxedema

A skin finding localized to the lower legs that is a characteristic feature of Graves disease.

Thyroid acropachy

A characteristic feature of Graves disease involving the clubbing of digits.

Anti-TRAb

TSH receptor antibodies used to confirm a high clinical suspicion of Graves disease.

Radioactive iodine uptake scan

A diagnostic imaging test used to differentiate causes of hyperthyroidism based on iodine accumulation patterns.

Diffuse pattern (on RAIU scan)

The radioactive iodine uptake pattern characteristic of Graves disease.

Toxic adenoma

A cause of hyperthyroidism indicated by a nodular pattern with a single area of accumulation on a radioactive iodine uptake scan.

Multinodular goiter

A cause of hyperthyroidism indicated by a nodular pattern with multiple areas of accumulation on a radioactive iodine uptake scan.

Hashitoxicosis

The early phase of Hashimoto thyroiditis characterized by low iodine uptake and positive anti-TPOAb and/or anti-TGAb.

Exogenous thyroid hormone use

A cause of hyperthyroidism characterized by low radioactive iodine uptake and low thyroglobulin levels.

Endogenous hyperthyroidism (e.g., thyroiditis)

A condition characterized by low radioactive iodine uptake and high thyroglobulin levels.