Pediatric Atypical Melanocytic Proliferations: Single-Site Retrospective Cohort Assessment of Treatment and Long-Term Follow-Up

Simple Summary Pediatric skin lesions of melanocytes are understudied, with limited data regarding long-term survival and treatment methods. Melanocytes are cells that produce melanin and cause pigmentation in the skin. The authors sought to add to the literature by looking at all cases of atypical melanocytic proliferations that were seen at our institution over a twenty-year period; there were 166 such cases. With these data, we compared the findings, such as follow-up time, location of disease, and treatment method, to other studies on childhood atypical lesions of melanocytes. Our findings were similar to prior studies in terms of location of primary disease and overall high survival rate. There were exceptions in positive lymph node rate for pediatric melanoma, a lower excision rate for atypical Spitz tumors, and a patient who died from atypical Spitz melanoma.Abstract Atypical and malignant cutaneous tumors are understudied in the pediatric population, with limited data on long-term follow-up. This study examines pediatric (0-18 years) atypical melanocytic proliferations over a twenty-year period (January 2002-December2022) using the EPIC SlicerDicer at our institution. Over a twenty-year period, there were 55 cases of pediatric melanoma (53 patients). The median follow-up time was 8 years, 11 months. A proportion of 96% were treated with wide local excision (WLE), and 47% had a sentinel lymph node biopsy (SLNB) (35% positive rate). There were 101 atypical Spitz tumor cases (85% atypical Spitz tumors, 15% Spitz melanoma), with a median follow-up duration of 9 years. A proportion of 77% were treated with WLE (with one patient dying of metastatic disease). There were 10 cases of atypical melanocytic proliferations not otherwise specified, including 5 pigmented epithelioid melanocytomas (PEM), 4 deep-penetrating nevi, and 1 atypical cellular blue nevus. This study adds to the growing body of knowledge on pediatric atypical cutaneous melanocytic proliferations, aligning with many described characteristics such as disease location and overall survival rates, with distinct exceptions (higher melanoma positive SLNB rate, lower atypical Spitz tumor WLE rate, and a case of fatal metastatic atypical Spitz tumor).