Endocrine Abstracts

Background: Parathyroid hormone-related protein (PTHrP) was discovered as a tumor product. It is also one of the complex epithelial and mesenchymal interaction signal mediator in breast development. An increase in the prevalence of malignancy in patients with Klinefelter’s syndrome, but not in patients with idiopathic gynecomastia has been previously reported. PTHrP may play a critical role in the development or progression of breast cancer.

Aim: We determined the PTHrP plasma level and investigated its potential role on idiopathic gynecomastia and gynecomastia which accompanies Klinefelter’s syndrome.

Materials and methods: In this prospective clinical study, 40 patients with gynecomastia (15 with Klinefelter’s syndrome, 25 with idiopathic gynecomastia) and 25 healthy controls were enrolled. Klinefelter’s syndrome was defined with regard to clinical, biochemical findings and karyotyping. Idiopathic gynecomastia was defined as breast enlargement, which could not be related with any disease despite extensive investigations.

Results: PTHrP levels altered between the Klinefelter’s syndrome and idiopathic gynecomastia groups (14.19±3.29 in patients with Klinefelter’s syndrome and 11.68±2.10 in patients with idiopathic gynecomastia, P=0.031). Serum alkaline phosphatase (ALP) level and sedimentation rate were higher in patients with Klinefelter’s syndrome compared to patients with idiopathic gynecomastia (129±32 U/l versus 97±34 U/l, P=0.007 for ALP and 8±9 mm/h versus 2±1 mm/h, P=0.001 for ESR respectively).

Conclusion: Our findings established that PTHrP levels do not have any direct effect on gynecomastia development. There is a statistically significant difference between the PTHrP level of patients with Klinefelter’s syndrome and idiopathic gynecomastia. The alterations in erythrocyte sedimentation rate and PTHrP may be an indicator of malignancy.