Immunohistochemistry and histopathology of two adjacent cutaneous scalp nodules from patient 1. (A) Immunohistochemical stain for Melan-A showing homogeneous staining of tumor. (B) Site of an adjacent pigmented lesion which previously had a clinical appearance like the lesion in panel A, but which had flattened over the course of vaccination. Pigment-laden macrophages but no residual melanoma cells are seen.