Endocrine Abstracts

Background: Parathyroid carcinoma accounts for <1% of cases of primary hyperparathyroidism. Clinical presentation is usually related to severe hypercalcemia associated to elevated serum PTH (three times above the upper limit). These values are so much higher than in primary hyperparathyroidism due to a benign adenoma. Moreover, 30–75% of patients had a palpable neck mass.

Clinical case: Fifty one-year-old male, submitted to bariatric surgery by a biliopancreatic diversion (Larrad’s technique) in 2002. He left treatment and follow-up at Nutrition Department. He is admitted to hospital because of an acute respiratory failure when a right cervical mass is discovered. TC showed a trachea deviation related to a 7 cm mass depending from the right thyroid lobe. FNA was suspicious for a follicular neoplasm with Hürthle cells. In previous analysis patient had many normal calcium values but some slightly elevated, chronic hypophosphatemia and very high intact PTH (values above 500 pg/ml, range 9–70). Surgery was performed including a total thyroidectomy, cervical exploration looking for any parathyroid adenoma and a tracheostomy. Histological study revealed a parathyroid carcinoma of 7.8 cm×4.6 cm×3.3 cm and one-gland hyperplasia. Patient developed a hungry bone syndrome with high needs of calcium and calcitriol. 25OHvitamin D was undetectable and post-surgical PTH was 178.5 pg/ml.

Conclusion: Main form of presentation of parathyroid carcinoma is severe hypercalcemia. However, our patient had a normocalcemic hyperparathyroidism. Absence of hypercalcemia despite of so high PTH is explained by a malabsortive bariatric procedure that excluded duodenum and first part of jejunum conditioning a chronic malabsortion of calcium and vitamin D.