A 58-year-old woman with long-standing Hashimoto's thyroiditis presents with rapid thyroid enlargement over 6 weeks and new hoarseness. What is the most likely diagnosis?

• A Anaplastic thyroid carcinoma
• B Medullary thyroid carcinoma
• C Reactivation of Hashimoto's thyroiditis
• D Primary thyroid lymphoma (MALT type) ✓

Explanation

Primary thyroid lymphoma, typically MALT (mucosa-associated lymphoid tissue) type, is strongly associated with Hashimoto's thyroiditis and presents with rapid thyroid enlargement in a patient with longstanding autoimmune thyroiditis. Hoarseness suggests local invasion. While anaplastic carcinoma also enlarges rapidly, the background of Hashimoto's makes lymphoma more likely and is the classic association tested.

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.