OBJECTIVES: I. Determine the toxicity of intralesional immunotherapy with a recombinant vaccinia virus encoding the gene for sargramostim (GM-CSF) in patients with metastatic melanoma. II. Determine the efficiency of viral infection and GM-CSF gene insertion and function in these patients. III. Determine the capacity of this regimen to generate antiviral and antitumor immunity in these patients. IV. Determine the frequency of regression of injected and uninjected lesions in these patients.