In this case report, a 62-year-old woman was diagnosed with lymph node metastasis from melanoma in the groin. Initially the primary tumour was unknown. The entire skin was examined without any suspicious moles. A PET-CT scan showed an area on the left heel with increased activity. The element surprisingly showed an amelanotic melanoma. Amelanotic melanomas have a significantly worse prognosis compared to pigmented melanomas, presumably because they are detected later and may be very difficult to detect clinically. This case shows the importance of paying attention to unpigmented elements when searching for a primary tumour.