Treatment outcomes following partial shave biopsy of atypical and malignant melanocytic tumors in pediatric patients.

Pediatric melanoma is the most common skin cancer in children and treatment relies on accurate staging. The American Academy of Dermatology recommends excisional biopsy for suspicious skin lesions, however, partial shave biopsies are often performed, the impact of which is unknown in pediatric and adolescent/young adult (AYA) patients. The aim of this retrospective case series study was to evaluate the impact of the diagnostic biopsy method on staging, treatment, and treatment-related outcomes in pediatric/AYA patients with melanoma. Among 103 pediatric/AYA patients with atypical cutaneous melanocytic lesions, the most common biopsy method was partial shave (68/103, 66.0%) followed by punch (20/103, 19.4%), excisional (14/103, 13.6%), and incisional nonshave (1/103, 1%). Over half of all biopsies yielded a positive deep margin, reflecting compromised microstaging (56/103, 55.4%), the majority occurred following partial shave (52/56, 92.9%) compared with other techniques (P < 0.001). All 11 patients with wider surgical target margins of wide local excision and 8/9 patients with sentinel lymph node biopsy performed due to positive deep margin, underwent a partial shave biopsy (P = 0.05 and 0.32, respectively). Almost half of all patients who underwent partial shave biopsy had a clinically suspected abnormal melanocytic tumor prior to biopsy (31/68, 45.6%; P = 0.03). Of 56 patients who had compromised microstaging, 17 (30.4%) had a diagnosis of melanoma (P = 0.17). Pediatric/AYA patients frequently undergo partial shave biopsy, which is associated with more invasive definitive surgical treatment due to compromised microstaging. These results may help optimize care of patients with cutaneous melanocytic tumors.