Scientists have discovered a diagnostic algorithm to distinguish two subtypes of malignant melanoma. Desmoplastic and spindle cell melanoma may look alike – they often resemble little scars or retractions of the skin – but differ in prognosis and therapeutic options. Sometimes even routine histology is not decisive because of partly overlapping features. The new algorithm, a combination of the biomarkers Melan A and trichrome, allows a diagnostic distinction of the subtypes.