Ultrastructural study of hereditary benign telangiectasia
Differential diagnosis from Osler Rendu disease. There are two hereditary forms of primary telangiectasia with a totally opposite prognosis. In Rendu-Osler disease, also called hereditary haemorrhagic telangiectasia, there is a major risk of severe haemorrhage in adults. In benign hereditary telangiectasia there is no such risk. We report two brothers who were diagnosed as having Rendu-Osler disease. Under standard electron microscopy, a biopsy of a telangiectasia taken from the right arm pit showed that the vessels of the superficial reticular derma were dilated with thick walls but no dehiscences as in Rendu-Osler disease. This ultrastructure explains why there had been no haemorrhages in our two cases and favoured a diagnosis of hereditary benign telangiectasia.