Diagnostic and Therapeutic Challenges in Parathyroid Cancers: 15 Years’ Experience in a Tertiary Center and an Endocrine Surgery Referral Hospital

<b>Background:</b> Parathyroid cancers are rare endocrine malignancies that pose diagnostic and therapeutic challenges, particularly when discovered incidentally or in the presence of multiple endocrine disorders. This study aims to provide clinical, biochemical and pathological insights into these malignancies through a retrospective case series. <b>Methods:</b> We analyzed retrospectively, from a tertiary and an endocrine surgery referral center, 13 cases of parathyroid cancers, where 4 cases were associated with thyroid cancers, including demographic data, clinical presentation, biochemical markers, imaging, surgical interventions, histopathological findings and follow-up outcomes. Descriptive statistics were used to summarize patient characteristics. <b>Results:</b> The median age of the cohort was 64 (range: 40-81 years), with a female-to-male ratio of 8:5. More than half of the cases (61.53%) were diagnosed incidentally, with common biochemical findings including elevated parathyroid hormone (PTH) levels (median: 430 pg/mL) and hypercalcemia in 80% of the patients. All patients underwent surgery, with parathyroid resections with concomitant total thyroidectomy (62%) or lobectomy (23%) as the most common interventions. Histopathological analysis confirmed parathyroid carcinoma in all cases, with coexisting thyroid malignancies observed in 31%. An immunohistochemical profile performed in about half of the patients was in accordance with previously published data. Postoperative normalization of PTH levels was achieved in 77% of patients, and no recurrence or metastasis was observed in 85% of cases during follow-up. <b>Conclusions:</b> Despite the exceptional rarity of the disease, this case series highlights the importance of preoperative biochemical and imaging evaluation and the efficacy of surgical management. Long-term outcomes remain favorable with early diagnosis and diligent postoperative monitoring. Further research into molecular biomarkers and targeted therapies is warranted to improve the management of advanced or recurrent disease.