Melanocytic tumour with unknown malignant potential--a Danish study of 67 patients

The aim of our single clinical centre study was to evaluate the risk of local metastases, lymph node metastases and distant metastases in patients diagnosed with melanocytic tumour with unknown malignant potential (MELTUMP). Furthermore, we evaluated several histologic tumour characteristics as potential predictive factors. From 1 January 1999 to 30 June 2011, a total of 67 consecutive patients were diagnosed with MELTUMP in our hospital. In this study, all the pathology slides were reviewed by the same independent expert dermatopathologist. All data were retrieved from patient charts. Four patients (6%) had regional nodal dissemination at the time of the diagnosis. Furthermore, one patient (1%) developed regional spread during follow-up and another patient (1%) died from distant metastases 1 year after diagnosis. We found no predictive factors with regard to histologic tumour characteristics. Our study confirms the low malignant potential of MELTUMP. We found a low risk of nodal metastasis and mortality from distant metastasis during follow-up. We recommend that all patients diagnosed with MELTUMP should be treated according to the guidelines for invasive melanoma.