Nonfunctional parathyroid carcinoma: two case reports and literature review

Abstract

Abstract Parathyroid carcinoma (PC) is a rare malignant endocrine tumor whoseunderlying pathobiological mechanism is still unclear. Herein, two cases of functioning/nonfunctioning PC are presented. Case 1 was a patient with a functional PC. The patient presented edema in both lower extremities causing pain and difficulty walking. The main clinical symptoms were elevated parathyroid hormone levels and hypercalcemia. A tumor mass of 27×37×41 mm in size waslocated below the right thyroid gland. The patientpresented evidence of multiple bone lesions, an abnormal increase in glucose metabolism, and left kidney atrophy with stones. Case 2 was diagnosed with non-functional PC. The patient presented no obvious clinical symptoms, but a thyroid nodule was diagnosed on physical examination. The nodule was 10 mm in diameter and waslocated below the left thyroid gland. Both patients were diagnosed by histopathological analysis and were treated by surgical excision; they received regular follow-up evaluations. Patient 1 died 18 months after surgery due to severe pulmonary infection and tracheal stenosis. Patient 2 survived without recurrence or metastasis. The diagnosis of PC relies mainly on apathological diagnosis, and surgical resection is the main treatment approach. Early diagnosis and complete resection of the lesion are key factors for defining prognosis. Postoperatively, patients require lifelong follow-up. Herein, we provide a description of the diagnostic workup and the treatment approach and review relevant studies. We summarize the clinicopathological characteristics of PC cases to provide evidence for early diagnosis and therapy, and to improve the prognosis of patients.