Unilateral Proptosis of Unexplained Origin Part Ii

ORBITAL exploration has shown that the two commonest causes of unilateral proptosis of unexplained origin are small cavernous haemangiomata and blood cysts in the muscle cone space not extending to the orbital apex The rare cases in which orbital exploration reveals no lesions and the proptosis continues to progress should be kept under observa- tion. The four cases to be described in this paper show how repeated skull x rays and ocular and orbital examinations determine the site and nature of the tumour and biopsy determines the pathology of the condition.