A 32-year-old woman presents with fatigue and weight gain. The thyroid is diffusely firm and painless. Biopsy shows dense lymphocytic infiltrate with germinal centers, atrophic follicles, and eosinophilic granular epithelial cells lining the follicles. Which antibody is most specific for this condition?

• A Anti-thyroglobulin antibody
• B Anti-collagen type II antibody
• C TSH receptor blocking antibody
• D Anti-thyroid peroxidase antibody ✓

Explanation

The histology of lymphocytic infiltrate with germinal centers, atrophic follicles and Hürthle cell (oncocytic) metaplasia is classic for Hashimoto thyroiditis. Anti-TPO antibodies are present in about 90 percent of patients and are the most sensitive and specific marker. Anti-thyroglobulin antibodies occur in only about 60 percent and are less specific, while TSH receptor blocking antibodies explain the hypothyroid phenotype but are not the standard diagnostic marker.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.