Seeking better resolution to magnetic resonance imaging recommendations for infants with congenital melanocytic nevi

Dear Editors: We appreciate the comment from Krengel et al1Krengel S. Ott H. Waelchli R. Recommendations for routine MRI in children with congenital melanocytic nevi need revision Comment to Neale et al.J Am Acad Dermatol. 2023; 89: e153-e154Abstract Full Text Full Text PDF Scopus (1) Google Scholar and recognize that conflicting recommendations for magnetic resonance imaging (MRI) screening of children with congenital melanocytic nevi (CMN) is a source of frustration for parents and physicians alike. Our study2Neale H. Plumptre I. Belazarian L. Wiss K. Hawryluk E.B. Central nervous system magnetic resonance imaging abnormalities and neurologic outcomes in pediatric patients with congenital nevi: a 10-year multi-institutional retrospective study.J Am Acad Dermatol. 2022; 87: 1060-1068https://doi.org/10.1016/j.jaad.2022.05.062Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar was in part inspired by patients with low-risk CMN presentations and parents seeking MRI for children without neurologic abnormalities who met certain criteria (having a CMN of >3 cm or multiple CMN) in a litigious climate regarding the possibility of “missing” a finding, albeit rare and potentially asymptomatic.3Frieden I.J. Williams M.L. Barkovich A.J. Giant congenital melanocytic nevi: brain magnetic resonance findings in neurologically asymptomatic children.J Am Acad Dermatol. 1994; 31: 423-429https://doi.org/10.1016/S0190-9622(94)70204-7Abstract Full Text PDF PubMed Scopus (153) Google Scholar,4Waelchli R. Aylett S.E. Atherton D. Thompson D.J. Chong W.K. Kinsler V.A. Classification of neurological abnormalities in children with congenital melanocytic naevus syndrome identifies magnetic resonance imaging as the best predictor of clinical outcome.Br J Dermatol. 2015; 173: 739-750https://doi.org/10.1111/bjd.13898Crossref PubMed Scopus (70) Google Scholar The lack of significant imaging findings among patients who underwent central nervous system imaging for reasons other than their nevus is useful for clinical care. For patients with more complex CMN presentations, the decision to screen remains challenging. We agree with Krengel et al1Krengel S. Ott H. Waelchli R. Recommendations for routine MRI in children with congenital melanocytic nevi need revision Comment to Neale et al.J Am Acad Dermatol. 2023; 89: e153-e154Abstract Full Text Full Text PDF Scopus (1) Google Scholar that “no strict number of CMN accurately dichotomizes patients into low and high risk.” Because risk for neurologic involvement is higher for individuals with >20 additional CMN, the rationale for MRI in these cases is clear-cut. However, is a patient with 15 CMN (likely reflecting similar mechanisms of genetic mosaicism5Kinsler V.A. Thomas A.C. Ishida M. et al.Multiple congenital melanocytic nevi and neurocutaneous melanosis are caused by postzygotic mutations in codon 61 of NRAS.J Invest Dermatol. 2013; 133: 2229-2236https://doi.org/10.1038/jid.2013.70Abstract Full Text Full Text PDF PubMed Scopus (228) Google Scholar as those with >20) “low risk” enough to defer imaging? The timing of examination may affect whether patients meet such criteria: dermatologists may assess a patient early in infancy, and additional CMN may become apparent throughout the first year. Screening decisions may have a clinical impact years later because baseline MRI studies are critical to identify evolving abnormalities if patients subsequently develop neurologic symptoms. We acknowledge the neurocutaneous melanocytosis (NCM) risk for multiple medium-sized CMN, but more data are needed on other complex presentations and neurologic associations of CMN. Our data included 18 patients with a medium CMN in addition to another nevus of equal or smaller size; of these 18 patients, 3 (17%) had concerning imaging findings: one required neurosurgical intervention and 2 had neurodevelopmental problems. Although this cohort is small and limitations exist, we err on the side of identifying intervenable abnormalities in at-risk groups until better data become available. There are nuances beyond the scope of our study that are relevant to the implementation of imaging recommendations. Clinical costs, insurance, or health care systems impact imaging availability. Technology ranges from quick MRI screening to detailed MRI protocols, which impact resolution and neurocutaneous melanocytosis detection. For patients as old as 2 years, a screening study would likely require both contrast (to detect neurocutaneous melanocytosis after myelination at approximately 6 months) and anesthesia (due to risk of motion artifact). Even among the 3 Northeastern academic medical centers in our study, there is variable access to MRIs and willingness to attempt a “feed and swaddle” protocol. When possible, for appropriate patients, we pursue MRI imaging during the first few months using a detailed MRI study without contrast or anesthesia.6Jahnke M.N. O’Haver J. Gupta D. et al.Care of congenital melanocytic nevi in newborns and infants: review and management recommendations.Pediatrics. 2021; 148e2021051536https://doi.org/10.1542/peds.2021-051536Crossref PubMed Scopus (11) Google Scholar In agreement with the recommendations of Krengel et al,1Krengel S. Ott H. Waelchli R. Recommendations for routine MRI in children with congenital melanocytic nevi need revision Comment to Neale et al.J Am Acad Dermatol. 2023; 89: e153-e154Abstract Full Text Full Text PDF Scopus (1) Google Scholar we are pleased to reassure parents of accepted low-risk CMN presentations. However, clinical decisions for more complex CMN presentations require a discussion and shared decision making between the clinician and caregiver, in the context of available imaging technology. None disclosed. Recommendations for routine magnetic resonance imaging in children with congenital melanocytic nevi need revision Comment to Neale et al., J Am Acad Dermatol. 87(5):1060-1068Journal of the American Academy of DermatologyVol. 89Issue 4PreviewTo the Editor: The article by Neale et al1 reviews 46 children with congenital melanocytic nevi (CMN), from the Boston Children’s Hospital and the University of Massachusetts Medical Center, who underwent magnetic resonance imaging (MRI) of the brain and/or spine. Seventeen percent of the children had melanin detected in the central nervous system (CNS) and 1 developed brain melanoma (fatal). Neale et al1 consider MRI important in young CMN patients to identify acute concerns and intervene surgically, to obtain a baseline, and to guide neurodevelopmental expectations. Full-Text PDF