Abstract
The hobnail variant of papillary thyroid carcinoma (HPTC) is a rare but highly aggressive form of thyroid cancer, associated with a more severe clinical course and significantly poorer prognosis compared to conventional PTC. To be classified as HPTC, a tumor must contain at least 30% of cells exhibiting hobnail-micropapillary features. These cells are characterized by distinctive papillary cytomorphology, including a hobnail-like appearance, the presence of papillae and micropapillae, high nuclear-to-cytoplasmic ratios, apically located nuclei, and prominent nucleoli. Additionally, some studies have reported associations between HPTC and specific genetic mutations, such as BRAFV600E, TP53, and TERT. In this article, we present the case of a 58-year-old male diagnosed with HPTC, managed with radiotherapy.