A Comparative Study on the Multidimensional Features of Hereditary and Sporadic Medullary Thyroid Carcinoma Patients: A Single-Center Retrospective Study

<i>Background and Objectives:</i> Medullary thyroid carcinoma is a rare neuroendocrine malignancy, with sporadic and hereditary forms accounting for 75% and 25% of cases, respectively. This study compares the clinicopathological features of sporadic medullary thyroid carcinoma (sMTC) and hereditary medullary thyroid carcinoma (hMTC) using real-world data to provide risk factors that aid in the early detection of the disease. <i>Materials and Methods:</i> The retrospective study comprised 77 patients with confirmed MTC treated at a tertiary referral center between January 2019 and December 2024. Patients were classified as hMTC (<i>n</i> = 11) or sMTC (<i>n</i> = 66) based on RET proto-oncogene (RET) genetic testing, whereas harboring a germline RET mutation indicated hMTC. Demographic, clinical, laboratory, radiological, histopathological, and genetic data were collected. <i>Results:</i> hMTC patients were significantly younger at diagnosis, with a comparable gender distribution (<i>p</i> = 0.738), and more often had a previous case of MTC within the family history. Pheochromocytoma occurred exclusively in hMTC. Multicentric tumors were more frequent in hMTC, and non-diagnostic Bethesda I cytology was higher in hMTC. <i>Conclusions:</i> While confirming established differences, this study provides detailed pre-operative diagnostic parameters and surgical approaches that can guide clinical decision-making in resource-limited settings where genetic testing may not be immediately available.