Which papillary thyroid carcinoma variant is defined by tumor cells whose height is at least two to three times their width in more than 30 percent of cells, and carries the worst prognosis among conventional papillary carcinomas?

• A Cribriform-morular variant
• B Diffuse sclerosing variant
• C Tall cell variant ✓
• D Oncocytic variant

Explanation

The tall cell variant requires that more than 30 percent of tumor cells be at least two to three times taller than wide, and it behaves more aggressively with higher rates of extrathyroidal extension, nodal metastasis, recurrence, and mortality. The cribriform-morular variant is associated with familial adenomatous polyposis and APC or WNT pathway alterations, while the diffuse sclerosing variant affects young patients and mimics Hashimoto clinically despite its extensive stromal fibrosis and squamous metaplasia.

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.