Fuchs D, Kilbertus A, Kofler K, et al. - Researchers investigated 1,145 patients [944 patients had systemic mastocytosis (SM) and 201 patients had cutaneous mastocytosis (CM)] from the European Competence Network on Mastocytosis (ECNM) registry who underwent a bone marrow biopsy to develop a risk score to predict SM in adults with mastocytosis in the skin (MIS). Tryptase level, constitutional/cardiovascular symptoms and bone symptoms/osteoporosis were independent predictors of SM in the multivariate model. A 6-point risk score was established and validated. Using a large ECNM registry dataset, the authors established a risk score to predict the presence of SM in MIS patients. Although the score would require further confirmation in independent cohorts, the score appears to discriminate safely between SM and pure CM patients.