Successful transurethral intralesional BCG therapy of a bladder melanoma.

An isolated metastasis of malignant melanoma to the urinary bladder of a patient was sucessfully eradicated by transurethral intralesional injection of BCG. Total destruction of the tumor was confirmed by subsequent excision. Lymphocyte blastogenesis studies revealed no significant alteration in immunocompetence secondary to the therapy, except for an increased responsiveness to PPD. There was no evidence of presence of blocking factors following therapy; cytotoxicity against MLA-14 melanoma cells sharply increased after the intralesional injection. Humoral antimelanoma antibody levels, determined by complement fixation, were decreased before the intralesional therapy, but increased markedly immediately following the transurethral BCG injection.