Another step on the road towards standardized outcome reporting for congenital melanocytic naevi: one more to go!
Authors: M.V. Heppt, T. Steeb, C. Berking
Journal: British Journal of Dermatology (2021)

Linked Article: Fledderus et al. Br J Dermatol 2021; 185:970–977. A core outcome set (COS) comprises a standardized consented minimum set of domain and outcome measurement instruments to facilitate uniform reporting in patient care and research. A COS is usually developed in a stepwise process starting from a set of domains to outcomes and, ultimately, to specific measurement instruments.1 While the first two items relate to what should be measured, the latter one defines how a condition of interest should be assessed. In this context, the Outcomes for COngenital MElanocytic Naevi (OCOMEN) group recently reached consensus on the domains to be included for large, giant or multiple congenital melanocytic naevi (CMN).2 In this issue of the BJD, Fledderus et al. take this initiative one step further and define for the first time a set of outcomes for both research and patient care.3 Adhering to a rigorous methodology and including all relevant stakeholders on an international level, a list of provisional outcomes for CMN was critically reviewed through an online questionnaire and further modified to provide clear definitions for every outcome. Thereafter, various stakeholders discussed the inclusion of potential outcomes in an online consensus conference. Finally, ten outcomes were selected for the COS in two online votings, nine of which applied to both care and research: (i) skin appearance: ‘size of CMN’, ‘colour of CMN’, ‘texture of CMN’ and ‘satellite naevi number’; (ii) quality of life: ‘emotional distress’; (iii) neoplasm: ‘presence of melanoma’; (iv) neurology: ‘neurological symptoms and signs’; (v) adverse events: ‘wound problems of the CMN’ and ‘scar problems’; and, for research only, (vi) pathology: ‘molecular characteristics’. Nine of ten outcomes were redundant for both patient care and research. This raises the question of whether two distinct COS are needed for this condition. In contrast, outcomes for other clinically relevant domains such as neuroimaging to rule out neurocutaneous melanocytosis and psychological functioning were not included in the final set of outcomes. The past two steps of the OCOMEN project are undoubtedly important milestones in the journey towards a uniform approach to CMN as a condition with high variability in its clinical features and a paucity of data. However, the most difficult step is still looming ahead: to define a core outcome measurement set based on specific measurement instruments. This endeavour is not entirely novel as several classification schemes have been proposed for CMN in the past.4 Within the OCOMEN initiative, Fledderus et al.3 agreed on size of the lesion, number of satellite naevi, colour and texture as outcomes for the domain ‘skin appearance’. These parameters were also part of a consensus-based scheme for the categorization of CMN published previously by an interdisciplinary panel of experts.5 In the next step, we will see how the COS of the OCOMEN initiative will differ from existing recommendations, and what additional value it will generate for physicians and patients. In particular, measuring the domains and outcomes relating to extracutaneous findings such as emotional distress or neurological symptoms and signs can add significant novelty and fill existing gaps as they are not sufficiently considered in current categorization schemes. Open Access funding enabled and organized by Projekt DEAL. Markus V Heppt: Conceptualization (equal); Data curation (equal); Methodology (equal); Project administration (equal); Software (equal); Supervision (equal); Writing-original draft (equal); Writing-review & editing (equal). Theresa Steeb: Conceptualization (equal); Investigation (equal); Methodology (equal); Resources (equal); Software (equal); Visualization (equal); Writing-original draft (equal); Writing-review & editing (equal). Carola Berking: Data curation (equal); Formal analysis (equal); Investigation (equal); Methodology (equal); Project administration (equal); Resources (equal); Supervision (equal); Writing-original draft (equal); Writing-review & editing (equal).