Thyroiditis: Differential Diagnosis
Thyroiditis encompasses several inflammatory conditions of the thyroid gland. Clinical presentation often varies between hyperthyroidism (early) and hypothyroidism (late).
1. Key Types
| Type | Key Features / Histology |
|---|---|
| Hashimoto | Autoimmune (anti-TPO/anti-thyroglobulin). Hürthle cells, lymphocytic infiltrate with germinal centers. |
| Subacute (de Quervain) | Self-limited; follows viral infection. Painful thyroid. Granulomatous inflammation. |
| Riedel | “Woody” (fibrotic) thyroid. IgG4-related. May mimic malignancy. |
2. Exam Must-Knows
- Hashimoto’s disease: Increased risk of non-Hodgkin lymphoma (B-cell origin). Clinically presents as a painless goiter and hypothyroidism.
- De Quervain (Subacute): Classic board association is a painful, tender thyroid after a recent viral illness. ESR is typically elevated.
- Postpartum Thyroiditis: A form of silent (painless) thyroiditis that occurs in the first year postpartum; transient hyper/hypothyroidism.
Pathology Board Hint: For test questions, remember: Hashimoto = painless, Hürthle cells, risk of lymphoma. Subacute (de Quervain) = painful, granulomas, viral trigger. Riedel = rock-hard (fibrous) thyroid.