High-Grade Papillary Thyroid Carcinoma, Diffuse Sclerosing Subtype: A Series of 18 Cases Detailing the Pathologic Features, Potential for Misdiagnosis, and Aggressive Clinical Behavior.

ABSTRACT: High-grade differentiated thyroid carcinoma is a novel classification defined by elevated mitotic count (MC) of ≥5/2 mm 2 and/or tumor necrosis. It may assume a phenotype of papillary thyroid carcinoma, diffuse sclerosing subtype (PTC-DS), and can be termed HGPTC-DS. A detailed clinicopathologic review was conducted on a large series of 18 cases of HGPTC-DS. A control group of 41 PTC-DSs with genomic data was also included. Histologically, HGPTC-DS showed typical features of PTC-DS and HG areas, often exhibiting solid architecture of uniform squamoid cells admixed with tumor necrosis, frequently the comedo type. All HGDTC-DSs had tumor necrosis. The MC was often low (median 1/2 mm 2 ). PTC nuclear features were retained and no nuclear pleomorphism was seen. HGPTC-DS was often subjected to

SUBMITTER: Ghossein RA 

PROVIDER: S-EPMC12405789 | biostudies-literature | 2025 May

REPOSITORIES: biostudies-literature