A parathyroid adenoma is a benign tumor of the parathyroid gland. It generally causes hyperparathyroidism; there are very few reports of parathyroid adenomas that were not associated with hyperparathyroidism. A human being usually has four parathyroid glands located on the back surface of the thyroid in the neck.
The regulation of vasculogenesis, haematopoiesis, angiogenesis, lymph angiogenesis and vascular permeability are very complex. Several molecules, such as the family of VEGFs (vascular endothelial growth factors) and other growth factors have been described as important regulators of tumour angiogenesis and lymph angiogenesis, and are thus considered important therapeutic targets. In the early 70s, Folkmanâs postulates showed that angiogenesis is a crucial step of neoplastic development and a vital parameter to understanding the process of cancer biology, first for his essential role in neoplastic proliferation by supplying the energy required for tumour growth, and because of its potential as a therapeutic target. Currently several pro or anti angiogenic drugs have been approved by the FDA or are in clinical trials. The VEGFs are important peptides that have been widely investigated in several conditions, physiological such as the growth of the endometrium and embryonic development and pathological such as in tumour growth and metastasis. The increased expression of VEGF in tumours has been associated with a poor prognosis or increased risk of recurrence or metastasis in several types of cancers. In recent years some studies have demonstrated the expression of VEGF family members and its receptors in angiogenesis and lymph angiogenesis of different thyroid lesions.
Generally, the expression of VEGF family members have a tendency to be higher in malignant than in benign lesions.
Last date updated on June, 2014