Primary cerebral hydatid cysts.

A review of primary cerebral hydatid disease in Australasia shows that twenty-nine cases of primary hydatid cyst of the brain have been recorded here during the last sixty years. The fact that such cysts are quite rare in countries where hydatid disease is relatively common has been stated previously by Dew (1934). In the opening paragraph of this article, Dew has clearly stated the basis for differentiating this type of cerebral cyst from secondary cerebral infestation: " As in the case of all organs, infestation of the brain with echinococcal disease may be either primary or secondary. In the former, the cysts are derived from hexacanth embryos, which, after passing through the liver and lungs, have been carried by the carotid arterial stream to the brain. Secondary cysts are metastatic, and result from the sowing by the blood stream of scolices, derived from a fertile primary simple cyst which has ruptured into the left side of the heart. It is obvious, although the fact has not been universally recognized, that the pathological and clinical aspects of these two types are very different . . ." The present article is concerned with an analysis of the twenty-nine recorded Australasian cases, which include five cases from the author's practice. Of the total twenty-nine cases, records of fourteen are contained in the Hydatid Registry of the Royal Australian College of Surgeons, five are recorded here, and the remainder are either referred to by Dew (1928) or have been published in early Australian medical periodicals. An excellent review of the literature of intracranial hydatids has been published by Langmaid and Rogers (1940), and reference should be made to their article for an historical account of this condition. Case Reports