Toxic multinodular goiter

Question 1

What are toxic mutinodular goiters?

Answer 1

Condition featuring multiple autonomously functioning nodules

Question 2

What is the pathophysiology of toxic multinodular goiters?

Answer 2

Chronic iodine deficiency/thyroid dysfunction → decreased hormone production → increased hypothalamic TRH secretion → persistent TSH stimulation of the thyroid gland → hyperplasia of thyroid nodules, some more active than others → multinodular goiter (nontoxic MNG)
(in some cases) → Multiple somatic mutations of TSH receptor occur in long-standing goiters (> 60% of cases) → autonomous functioning of some nodules (toxic MNG) → hyperthyroidism (due to ↑ release of both T3 and T4)

Question 3

What are the clinical features of multinodular goiters?

Answer 3

Hyperthyroidism and multinodular goiter

Question 4

How is toxic multi-nodular goiter diagnosed?

Answer 4

↑ T3 with ↓ TSH
(Thyroid scintigraphy) radioiodine uptake by the hyperfunctioning nodules with suppression of the rest of the gland
(Histopathology)

Question 5

What is the treatment for toxic multinodular goiter?

Answer 5

same as for toxic adenoma

surgery