Endocrine Abstracts

Background: Parathyroid carcinoma (PC) is a rare cause of primary hyperparathyroidism (PHPT), accounting for <1%, with an equal gender distribution and an average age of diagnosis in the fifth decade of life. The diagnosis of PHPT is based on the laboratory finding of high levels of immunoreactive PTH in the presence of severe hypercalcaemia. The only potentially curative treatment for PC is surgery. Early surgery is the most important factor for optimal outcome.

Methods: This case series is based on a multidisciplinary review of four patients with parathyroid cancer, describing their therapeutic management and follow-up. Imagistic evaluation was performed by ultrasound (US), computed tomography scan (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and Technetium-99m sestamibi scintigraphy, for detecting the primary tumour, its local extent and remote metastases.

Results: Between 2008 and 2014 four patients were diagnosed with PC in our clinical department, three men and a woman, with a mean age of 50 years±S.D. 13.22 (range 38–68). None had family history of hyperparathyroidism or hormonal disorders suggesting multiple endocrine neoplasia. All had severe hypercalcaemia (15.3–19.4 mg/dl) and elevated PTH levels ranging from 15 to 45 times above normal value. Tumor size ranged from 3.2 to 7 cm; two of them had thyroid gland invasion and one thymic invasion. Three patients underwent parathyroidectomy with hemithyroidectomy and one underwent parathyroidectomy with thymectomy and cervical dissection. Schulte stage at diagnosis was between II and IV, while all were classified as high risk. Conformational radiotherapy of the tumor bed was used in two cases. Cinacalcet treatment was tried in one case and chemotherapy regimen in another, without significant improvement. Three patients had local recurrence and the time from the initial surgery to recurrence ranged from 1 month to 1 year.

Conclusion: Parathyroid carcinomas are rare endocrine cancers, with high relapse rate and poor prognosis. Multidiscplinary approach requires detailed imaging, skilled surgeons, endocrinologist and oncologist.