HERETOFORE, studies of malignant melanoma, our own as well as those reported by others, have dealt chiefly with the clinical aspects of the disease in living patients. The present investigation was undertaken primarily in an attempt to evaluate the biologic behavior of fatal lesions. It was based upon the records of 222 patients who were treated at the M. D. Anderson Hospital, all of whom have died within the past several years, their course having been followed to the time of death.
A classification of melanoma according to the clinical and pathological evidence of its extent was developed in this hospital nine years ago (Table 1). This classification was used in staging the disease of the 222 patients. In every case, the presence of melanoma was established by histological findings. The primary tumors (stage 1) of some of the patients had been removed previously, and neither tumors nor slides were