Nonfunctional parathyroid cancer − a case report

Abstract

Introduction: Parathyroid cancer is a rare endocrine malignancy. These tumors are typically functional, causing severe hypercalcemia due to primary hyperparathyroidism. Nonfunctional parathyroid cancer with normal serum calcium and parathyroid hormone levels is extremely rare. The disease is usually indolent but progressive with a tendency to metastasize. It is very difficult to diagnose this malignancy. The definitive diagnosis is made by histopathological examination. Radical surgery with ipsilateral lobectomy and en bloc neck dissection is considered to be the most appropriate therapeutic approach. There is no evidence of efficiency of adjuvant cancer therapy and its indication has not been defined. Disease recurrence is common. Case report: We report the case of a 26-year-old female patient who underwent left hemithyroidectomy for growth progression of a hypoechoic lesion behind the left thyroid lobe detected by ultrasonography. Preoperative cytology and imaging assessments were not suspicious for malignancy. Serum parathyroid hormone and calcium levels were normal. The diagnosis of nonfunctional parathyroid carcinoma was determined based on histopathological examination. No further surgery or adjuvant therapy was indicated. No signs of recurrence or generalization have been observed at 36 months after the surgery. Conclusion: Nonfunctional parathyroid cancer is extremely rare. In many cases, the diagnosis is made in advanced stages of the disease. No formal classification or treatment protocol has been established so far. A new staging system has been proposed in the 8th edition of AJCC/UICC. Early detection, radical surgery and close follow-up are crucial aspects to affect the mortality and morbidity of patients with this type of malignancy.