Background: Vascular malformations frequently enlarge during adolescence, suggesting that hormones may be involved. The purpose of this study was to determine whether pubertal hormone receptors are present in vascular malformations and whether they differ from normal tissue.
Methods: Tissue specimens (arteriovenous malformation, lymphatic malformation, and venous malformation) were prospectively collected from patients undergoing resection. Immunohistochemistry was used to determine the presence of androgen, estrogen, progesterone, and growth hormone receptors. The effects of age, sex, location, and malformation type on receptor expression were analyzed. Age-, sex-, and location-matched normal tissues served as controls.
Results: Forty-five vascular malformation specimens were collected: arteriovenous malformation (n = 11), lymphatic malformation (n = 20), and venous malformation (n = 14). Growth hormone receptor expression was increased in arteriovenous malformation (72.7 percent), lymphatic malformation (65.0 percent), and venous malformation (57.1 percent) tissues compared with controls (25.8 percent) (p < 0.05). Growth hormone receptor was present primarily in the endothelium/perivasculature of malformations (93.1 percent), whereas in normal tissue growth hormone receptor was located only in the stroma (p < 0.0001). Neither age, nor sex, nor location influenced receptor expression (p = 0.9). No differences in androgen receptor, estrogen receptor, and progesterone receptor staining were found between malformations and control samples (p = 0.7).
Conclusions: Growth hormone receptor is overexpressed and principally located in the vessels of vascular malformations. Growth hormone might contribute to the expansion of vascular malformations.