Parathyroid Carcinoma

Excerpt

Parathyroid carcinoma represents a rare malignancy of the parathyroid glands, most often arising sporadically but sometimes associated with genetic syndromes, eg, multiple endocrine neoplasia (MEN) syndrome types I and IIa and hyperparathyroidism-jaw tumor (HPT-JT) syndrome. This carcinoma accounts for fewer than 1% of primary hyperparathyroidism cases and occurs equally in men and women, most commonly during midadulthood. Loss of tumor suppressor function, frequently through HRPT2/CDC73 mutations, drives disease progression by promoting excessive hormone secretion and aggressive local invasion.

Histopathologic confirmation requires identification of capsular or vascular invasion, while parafibromin loss assists in distinguishing carcinoma from benign lesions. Clinically, suspicion increases with the presence of a firm neck mass accompanied by severe hypercalcemia, making comprehensive history-taking and physical examination essential for early recognition. Biochemical testing and imaging modalities, including ultrasound, sestamibi scanning, and 4-dimensional computed tomography (4D-CT), guide lesion localization, and advanced positron emission tomography/computed tomography (PET/CT) techniques contribute to the detection of metastatic disease.

En bloc surgical resection remains the primary treatment and offers the best chance for long-term survival, though recurrence frequently complicates outcomes and often necessitates systemic therapy or targeted medical management. Differential considerations include benign parathyroid adenomas, thyroid nodules, and metastatic tumors, yet no standardized staging system exists. Prognosis depends largely on early complete resection, while recurrence and hypercalcemia drive long-term morbidity and mortality. Complications stem both from the endocrine effects of the tumor and from risks associated with surgical and medical interventions. Effective patient education, combined with interprofessional coordination, ensures timely diagnosis, appropriate treatment, and structured long-term surveillance in this challenging disease.