Endocrine Abstracts

Introduction

Parathyroid carcinoma (PC) occurs in 0.5–5% of cases among patients with primary hyperparathyroidism (pHPT). The prognosis for patients with PC is variable and depends on the presence of local or distant metastases and the completeness of the initial surgery. About 50% of patients become recurrence of the disease and require palliative surgery and/or drug therapy aimed at correcting severe hypercalcemia.

Objective

To assess the experience of diagnosis and management of PC in the Republican clinical oncological dispensary (RCOD) of the Ministry of Health of the Republic of Tatarstan (Kazan, Russia) in the period from 2008 to 2020.

Subjects and methods

Medical records of 8 patients with PC treated in RCOD from 2008 to 2020 were analysed.

Results

2 men aged 35 and 50 years and 6 women aged 29–76 years included in this review. 6 patients had symptomatic HPT with bone and visceral involvement, 2 had a pre-diagnosis of a thyroid tumor with mass-effect symptoms. Parathyroid hormone (PTH) varied from 350 to 3227 pg/ml (15–65), serum calcium (Ca) – from 2.77 to 3.35 mmol/l (2.0–2.57). According to ultrasound imaging, MIBI-scintigraphy, neck and chest CT PC was located on the neck in 6 patients, retrosternal – in 1 patient, in the upper mediastinum – in 1 patient. All patients received surgical treatment: 5 patients underwent hemithyroidectomy with PC removal; 1 – thyroidectomy with PC removal and central lymph node dissection; 1 – cervicotomy, sternotomy, PC removal; 1 – videothoracoscopic PC removal. Histologically and immunohistochemically PC was verified in all cases. 7 of 8 patients are alive. Recurrences of PC manifested with an increase of PTH and Ca, occurred in 2 patients. Paratracheal lymph nodes metastases were detected in male patient 5 years after the initial surgery. Multiple bones and lung metastases were diagnosed in female patient 1.5 years after first surgery. Both patients underwent palliative surgery. The persisting severe hypercalcemia after surgery in the female patient was successfully corrected with cinacalcet and denosumab for 9 months. Female patient died 3 years after the initial surgery due to hypercalcemic crisis and multiple organ failure. The male patient is alive, has mild hypercalcemia and continues treatment with bisphosphonates and calcimimetics.

Conclusion

Diagnosis of PC and its recurrence is a difficult task for the practitioner. The main method of treatment remains surgical. Hypercalcemia, which develops during the dissemination of the process, requires long-term medical correction with antiresorptive drugs and calcimimetics.