Hypercalcaemic encephalopathy due to metastatic parathyroid carcinoma

A 49-year-old man presented in the emergency department with altered sensorium and renal failure and was placed on a ventilator. Evaluation with MRI of the brain showed enhancing lesion in the occipital lobe. Biochemical tests revealed elevated calcium and parathyroid hormone (PTH) levels. Further evaluation revealed multiple lesions at both lobes of the lungs and nodular lesion in the right inferior pole of the thyroid. Diagnosis of metastatic parathyroid carcinoma was suspected. Patient was stabilised with bisphosphonates and haemodialysis and planned for surgery. Intraoperatively a hard lesion was found in the right inferior parathyroid infiltrating the surrounding structures. En bloc resection was done. General condition of the patient improved and he was weaned from the ventilator. Histopathology confirmed the diagnosis of parathyroid carcinoma. Postoperatively, there was persistent elevation of PTH in spite of a fall in calcium levels indicating functioning brain and pulmonary metastases. Due to extensive metastases, the patient was given palliative cinacalcet and was kept under follow-up.