Florida cluster of five children with endodermal sinus tumors. Possible environmental risk.

An unusual case clustering of endodermal sinus tumors in Jacksonville, Fla., is described, together with a variety of local environmental risk factors. Proximity to high-tension electrical power lines was observed, but chance aggregation of familially disposed persons or coincidental environmental factors not identified could also be responsible. However, this cluster is too remarkable to go unreported and is presented here as a preliminary report for those interested in the epidemiology of rare tumors, in an attempt to probe this peculiar episode of cancer. Further investigation of cancer clusters is encouraged, with suggestions to maintain surveillance for these types of clusters in comparably affected areas.