Eight patients with hereditary hemorrhagic telangiectasia and severe epistaxis were treated with norethynodrel with mestranol (Enovid). Biopsy specimens of typical lesions from two patients were taken for electron microscopy before and after several months of therapy.
Characteristic endothelial cell damage and necrosis were noted in the dilated venules of patients before treatment but not after. Unlined channels of blood were found in connective tissue before treatment but not after. These are thought to arise from leaks in the affected venules, and it is suggested that later endothelial ingrowth gives rise to new telangiectasias and may account for the propagation of lesions that are known to develop with age.
Reduplicated basal laminae and regenerating endothelial cells were found both before and after treatment.