The following is a summary of “Ambiguous melanocytic lesions: A retrospective cohort study of incidence and outcome of melanocytic tumor of uncertain malignant potential (MELTUMP) and superficial atypical melanocytic proliferation of uncertain significance (SAMPUS) in the Netherlands,” published in the MARCH 2023 issue of Dermatology by Wang, et al.

Melanocytic tumors are skin growths that can be difficult to categorize as either benign or malignant. MELTUMP (melanocytic tumor of uncertain malignant potential) and SAMPUS (superficial atypical melanocytic proliferation of uncertain significance) are provisional terms used to describe such growths. For a study, researchers sought to determine the incidence and clinical outcomes of MELTUMP and SAMPUS in the Netherlands. 

The study reviewed all diagnoses of MELTUMP and SAMPUS in the Dutch Nationwide Pathology Databank from 1991 to October 1, 2021. Clinical outcomes were observed for cases diagnosed until October 1, 2018. Results indicated that there were 1,685 MELTUMP and 1,957 SAMPUS identified with an annual incidence rate of 150 to 300 cases. 

Metastatic behavior was seen in 0.7% of all initially diagnosed MELTUMP, but no metastases were seen in SAMPUS. However, the reassessment of pathology slides and confirmation of clonality between primary and metastatic lesions were outside the scope of the study. 

In conclusion, the study demonstrated that MELTUMP has a low malignant potential, while SAMPUS has no malignant potential. It was essential to seek expert advice for ambiguous melanocytic lesions, and the terminology for MELTUMP/SAMPUS should only be used for legitimately uncertain or unclassifiable cases.