Clinicopathological features of rare subtypes of papillary thyroid carcinoma
CHEN Chun-yan
LIU Zhi-yan
Abstract：Papillary thyroid carcinoma(PTC)is the most common thyroid malignancy,and a subset of subtypes exhibits moderate to high aggressiveness;accurate recognition is pivotal for prognostic assessment and individualized management.The fifth edition of the World Health Organization(WHO)classification emphasizes an integrated histologic-molecular diagnostic paradigm and,for the first time,explicitly designates high-risk histologic subtypes,including the tall cell subtype,hobnail subtype,and columnar cell subtype.Although the diffuse sclerosing subtype and the solid/trabecular subtype are categorized as intermediate risk,they likewise carry a considerable risk of metastasis.Distinct molecular profiles characterize these subtypes:the diffuse sclerosing subtype frequently harbors RET fusions;the tall cell subtype commonly shows BRAF V600E and TERT promoter mutations;and the hobnail subtype is closely associated with TP53 mutations.High-grade PTC,defined by tumor necrosis and a high mitotic rate,demonstrates biological behavior approaching that of poorly differentiated thyroid carcinoma.Standardized pathologic diagnosis requires adequate sampling in combination with immunohistochemistry and molecular testing to minimize misdiagnosis or underdiagnosis.Molecular subtyping further informs risk stratification and selection of targeted therapies.Overall,the diagnosis of rare PTC subtypes is transitioning from morphology alone to integrated molecular pathology,thereby laying the foundation for precision medicine and individualized treatment.
Keywords：papillary thyroid carcinomaWHO classificationrare subtypesdiagnostic pointsmolecular characteristics
Publication Date：2025-09-01
Online Publishing Date：2025-10-22(First online date of this platform, not the publication date of the document)
Pages：5( 996-1000 )