Which condition presents as a tender thyroid and transient hyperthyroidism?

The condition that presents as a tender thyroid and transient hyperthyroidism is subacute granulomatous (De Quervain) thyroiditis. This inflammatory disease of the thyroid gland typically follows a viral infection, resulting in a painful or tender, enlarged thyroid gland. The inflammation disrupts normal thyroid function, leading to the release of thyroid hormones into the bloodstream, which can cause transient hyperthyroidism.

In this condition, the tenderness is a key distinguishing feature, as it is often accompanied by symptoms such as a painful, tender neck and possible fever and malaise. The hyperthyroid phase is usually temporary, followed by a period of hypothyroidism before the thyroid function normalizes.

Hashimoto's thyroiditis, in contrast, is characterized by a chronic, painless process resulting in gradual destruction of thyroid tissue, and while it can cause hypothyroidism, it does not typically present with transient hyperthyroidism or significant tenderness.

Reidel fibrosing thyroiditis is associated with a significant fibrotic process leading to a hard, woody thyroid gland, but again, it does not present with tenderness or transient hyperthyroidism.

Thyroid storm is an acute, life-threatening condition characterized by severe hyperthyroidism symptoms, typically without a tender thyroid gland