Difficulties in the management of a parathyroid carcinoma - case-report

The case of a parathyroid carcinoma in a 61-year-old woman is described. The patient was referred to our hospital, with the diagnosis of medullary thyroid carcinoma, after a prior thyroidectomy performed at another hospital. On admission, serum calcium was 3.92 mmol/l (n.r. 2.2-2.5), PTH level was 320 ng/l (n.r. 10-65), urinary cAMP was 508.9 mmol/mmol creatinine (n.r. 330- 630) and serum calcitonin was 2.1 ng/l (n.r.<10). The patient was then submitted to a complete neck exploration and multiple nodules were removed. Histopathological diagnosis of parathyroid carcinoma was made by local recurrence and retrospectively upon closer examination of the original specimen. After surgery, normocalcemia was achieved and maintained for about four months. Serum PTH decreased to 28.8 ng/l after surgery but increased quickly to 75.6 ng/l ten days later. Three months later, there was both biochemical and clinical evidence of disease. In the following eight months, calcium levels ranged from 2.99 mmol/l to 4-24 mmol/l and PTH from 135 ng/l to 1431 ng/l. However no distant metastases were found. To Control hypercalcemia, the patient was treated with bisphosphonates but normocalcemia was never achieved. A slight and transient reduction in serum calcium as response to an acute administration of octreotide, made us not to consider this eventual modality of therapy. Sonographically guided percutaneous injection of ethanol was performed but the treatment was not found to be effective. Finally, the use of chemotherapy with 5-fluorouracil, cyclophosphamide and dacarbazine was also unsuccessful. The patient died two years after the initial diagnosis.