Parathyroid carcinoma presenting with chronic renal failure and single pulmonary metastasis: A case report

INTRODUCTION: Parathyroid carcinoma is a rare malignancy. Our case report is unusual for its presentation. The patient referred symptoms compatible with CRF; nodular lesions to parathyroid glands and an elevated PTH induced physician to hypothesize secondary hyperparathyroidism. The presence of haemoptysis gave us suspicion for malignant neoplasm but only histological examination allowed us to recognize the nature of the lesion, because even PET-CT didn’t detect, an hypercaptation in the parathyroids. PRESENTATION OF THE CASE: The case concerns a 59 years old female with the following symptoms: asthenia, oliguresis, nausea, haemoptysis and very high levels of calcium and PTH. Laboratory findings (PTH 570 pg/ml; Ca 12.20 mg/dl; P 1.8 mg/dl), ultrasound, CT scan and parathyroid scintigraphy, associated with clinical data, indicated a parathyroid carcinoma with single pulmonary metastasis of the upper lobe of the left lung, confirmed by histological examination and immunochemistry. Cytology performed with bronchoscopy was negative. Surgery (“en bloc” parathyroidectomy on adjacent structures, lymph node dissection near recurrent nerve and atypical lung resection) was effective, with normalization of calcium and PTH levels and disappearance of symptoms after 48 h. After six months, no signs of local recurrence or metastases were observed. DISCUSSION: No clinical or bio-humoral data allows a preoperative diagnosis of parathyroid carcinoma. Only with definitive pathology and immunochemistry it is possible to differentiate an adenoma from a carcinoma. CONCLUSION: In patients with CRF it’s difficult to diagnose parathyroid carcinoma, because its presentation mimics the most common secondary hyperparathyroidism; the concomitant presence of metastases should lead us to suspect malignant parathyroid lesions. Surgery is the only effective therapy and therefore should be always performed.