Endocrine Abstracts

Introduction: Primary hyperparathyroidism is a common disease. It is generally caused by a solitary parathyroid adenoma. Adenomas weighing more than 3.5 g are classified as giant. These giant parathyroid adenomas constitute a rare clinical entity.

Case report: A 54-year-old woman was referred to our ENT department for management of newly diagnosed hypercalcaemia. She had no significant medical history. She reported mild constipation, muscular weakness, nausea and intermittent abdominal pains since 1 month. There was no palpable mass on cervical examination. Biochemical evaluation revealed severe hypercalcemia (serum calcium: 5.54 mmol/l); the levels of serum parathormone were also elevated (2268 pg/ml). Cervical ultrasonography revealed a hypoechoic mass, measuring 3 cm, with augmented vascular Doppler signal at the periphery, which appeared to correspond to the right inferior parathyroid gland. There was no significant lymphadenopathy. A Tc99 m SestaMIBI scintigraphy showed an uptake compatible with an adenoma of the right inferior parathyroid gland extending into the mediastinum. Computed tomography of the neck and chest confirmed the presence of a lesion in the projection of the right inferior parathyroid gland extending to the anterior mediastinum measuring 5.94 cm × 2.71 × 2.05 cm. The severe hypercalcemia was temporarily controlled by hydration, forced diuresis and bisphosphonates. The parathyroid adenoma was successfully removed through a transcervical approach. Histopathological examination confirmed a benign giant parathyroid adenoma. The patient’s postoperative course was uneventful. Her serum calcium and PTH levels normalized quickly. She is currently asymptomatic and normocalcaemic.

Conclusions: Diagnosis of a giant solitary parathyroid adenoma is based on clinical pre-sentation, biochemical profile, and imaging studies. The parathyroid carcinoma is the principal differential diagnosis. The treatment is based on surgical excision combined with PTH levels measurement.