Humoral hypercalcaemia of benignancy. A case report

Abstract

Sir, Humoral hypercalcaemia of benignancy is characterized by a benign tumour producing hypercalcaemia induced by parathyroid hormone related protein (PTHrP). This condition is rare. Five previous cases have been reported in English, an ovarian dermoid cysts, mammary hyperplasia1 two cases related with uterine leiomyoma,2 and one with phaeochromocytoma.3 A possible association with an intestinal leiomyomyoma has also been reported. We present a case of PTHrP secreting benign uterine leiomyoma. Association was confirmed by normalization of calcium levels after tumour resection. Hypercalcaemia associated with malignancy is common, but is rarely associated with benign conditions. Hypercalcaemia of malignancy could be due to osteolytic metastasis or humoral, mediated by PTHrP. Tumours of lung, breast, prostate and some haematological malignancies are commonly associated with PTHrP-mediated hypercalcaemia. Benign tumours arising from endocrine tissues can often secrete hormones that cause their characteristic presentation. Benign tumours of non-endocrine tissues producing functionally relevant hormones are rare, but there are limited reports PTHrP produced in benign tumours. Our case adds to this limited number of reports …