A highly sensitive method to detect melanoma micrometastasis by examining lymph nodes for the presence of tyrosinase messenger RNA. In a preferred mode, this is accomplished using the combination of reverse transcription and double round polymerase chain reaction (RT-PCR). The amplified samples are examined on a 2% agarose gel and tyrosinase is seen as a 207 base pair fragment. The lymph nodes examined are determined using pre- and intra- operative node mapping.