Endocrine Abstracts

Introduction

The atypical parathyroid adenoma is a histological diagnosis. It is a parathyroid tumor with atypical histological features different from an adenoma and not similar enough to be considered as a carcinoma.It has an uncertain malignant potential.

Observation

We report the case of a 55 year-old woman, referred to us by her rhumatologist after discovering a severe hypercalcemia when exploring her for osteoporosis. The biology found a high level of calcium 3.68 mmol/l, and a very important level of parathormone PTH 1325.62 pg/ml (20 fold the normal level), confirming the diagnosis of primary hyperparathyroidism. The cervical ultra sound revealed a left hyperechoic, heterogeneous parathyroid mass, measuring 2.05 × 3.97 × 3.18 cm in diameter and a normal thyroid gland, and the Sestamibi-scintigraphy showed a large left inferior parathyroid adenoma. In front of this large mass, the severe hypercalcemia and the very high level of PTH, the malignancy was suspected and we completed the exploration by dosing two biomarkers of malignancy, the alkaline phosphatase ( ALP ) which was at 420 U/l (3 fold normal level ) and the BHCG was high at 4.09 mUI/ml. Before referring the patient to surgery, she received an intravenous bipohosphonate therapy to control the hypercalcemia, then she underwent a parathyroidectomy and a lobo-isthmectomy with no post operative complications and the level of calcium normalized to 2.25 mmol/l and the PTH level dropped to 152 pg/ml. On the examination of the removed tissue, the histo-pathological exam concluded to an atypical parathyroid adenoma.

Conclusion

The atypical parathyroid adenoma is a very rare tumor, and the diagnosis is still a challenge, the outcome of patients is not well known yet, there for the surveillance is important and must be regularly.