Additional Literature on “Vasculogenic Mimicry” not Cited

We have read the paper by Maniotis et al (Am J Pathol 1999, 155:739–752) reporting that “vasculogenic mimicry” may be induced by human melanoma cells. A paper by B. A. Warren (J R Microscop Soc 1966, 86:177–187) and another by Warren and Shubik (Lab Invest 1966, 15:464–478) reported an identical finding in a transplanted malignant melanoma of the hamster. Shubik later referred to this observation in a review on the vascularization of tumors published in 1982 (Can Res Clin Oncol 1982, 103:211–226). This observation was part of a series of studies on angiogenesis undertaken by a group of us including M. Greenblatt, A. G. Sanders, and M. Goodall in Chicago during the 1960s. One is no longer surprised to learn that findings published 30 years ago are not usually referenced since they have become extremely difficult to find in current electronic library indices.