Concomitant conjugal gliomas with similar histologic features.

Conjugal tumors are rarely reported; but nevertheless, raise important questions of possible etiologic factors. In this report, the presentation of grade 2 gemistocytic astrocytomas in an unrelated married couple in their early thirties within 18 months of each other is described. In both cases the left frontal region of the brain was involved and histologically the tumors were very similar. Although there are no accurate figures on the true incidence of gliomas, an estimate can be derived from reliable epidemiologic studies of primary brain tumors as a whole. Using such data, it is calculated that the risk of two designated persons developing a grade 1 to 2 astrocytoma while in the fourth decade within the same year is approximately 1 in 30 billion (10(9)) and, for this couple, over a period of 15 years, at least 1 in 185 million. No specific causative environmental factors were identified in the patients, and results of conventional tests for viral and other infections were negative. It is postulated that apart from remote chance, such conjugal lesions implicate the action of an environmental agent. In the absence of other factors, involvement of a slow, unconventional virus is a possibility that must be strongly considered.