Intracranial Hodgkin's disease shown by radioisotope scan.

Verified intracranial deposits of Hodgkin's disease are rare. Thus there was only one among 125 cases reported by John and Nabarro (1955). In the monograph by Williams, Diamond, Craver, and Parsons (1959) there were four among 1,992 cases. Todd (1967) reported two among 1,339 cases. The deposits are usually subdural, intracerebral metastases being exceptional. This rarity contrasts with the incidence of spinal extradural deposits, around 5% in most series (Goldman, 1940; Smith and Stenstrom, 1948; Verity, 1968; Currie and Henson, 1969); the absence of a true intracranial extradural space may be a factor, as pointed out for lymphosarcoma by Jemstrom, Crockett, and Bachhuber (1966). In only two of the cases of subdural metastasis recorded in the literature has intravenous gammaencephalography been carried out (Gaelen and Levitan, 1967; Verity, 1968), in each as an adjunct to contrast studies (arteriography and pneumography). Its use is described in a further case which presented with epilepsy and was confirmed at necropsy. Its place in the investigation and management of similar cases is discussed; this is pertinent as, firstly, the rarity means that a coincidental lesion needs exclusion and, secondly, the relatively benign nature of most deposits, which are solitary and compress rather than invade brain, makes their demonstration more than an academic exercise.