[Tumor-associated hypercalcemia syndrome in patients with squamous cell carcinomas of the head and neck. Differential diagnosis of a paraneoplastic syndrome].

Hypercalcaemia in squamous cancer of head and neck is not uncommon. Atypical symptoms make the diagnosis difficult. Immediate therapeutic intervention is necessary to prevent life-threatening complications. The causes include dietary calcium excess, vitamin-D-intoxication, bone metastasis and primary hyperparathyroidism. The paraneoplastic syndrome of ectopic hyperparathyroidism leading to the hypercalcaemia syndrome is induced by several different hormones. Ectopic production of parathyroid hormone or similar substances, increased synthesis of prostaglandins and vitamin-D-like steroids are proposed. Two typical cases are demonstrated.