25. Subacute granulomatous thyreoiditis (De Quervain)

Overview. Even at this magnification can you see that there is fibrosis surrounding small “islands” of thyroid follicles. The bright, left area of the slide is where it is easiest to find giant cells.

Staining: HE

Organ: Thyroid

Description:

Areas of normal thyroid is separated by fibrosis, causing the formation of “islands” of thyroid follicles. Also present are some giant cells, indicating that this is a granulomatous inflammation.

Diagnosis: Subacute granulomatous thyroiditis / de Quervain’s thyroiditis

Islands

Causes:

• Viral infection, often upper respiratory tract

Theory:

Comparison between giant cells and thyroid follicles

This is a self-limiting disease that goes away after 6-8 weeks without treatment. Fibrosis is only present in the late stages of this condition, either right before or after remission. This indicates that this sample was taken from a patient who had late-stage subacute granulomatous thyroiditis. This also explains why there are so few giant cells present.

Giant cells