Purpuric Patches as Cutaneous Presentation of Pediatric NTRK ‐Rearranged Spindle Cell Neoplasm

Neurotrophic tyrosine receptor kinase‐rearranged spindle cell neoplasms (NTRK‐RSCNs) are rare soft tissue tumors with a broad histologic spectrum. Limited data exist on their cutaneous manifestations, particularly in pediatric patients. We present the case of a 4‐year‐old girl with an LMNA‐NTRK1 fusion‐positive spindle cell neoplasm initially presenting as a subcutaneous nodule adjacent to purpuric patches on the abdomen. This case highlights an atypical cutaneous presentation of NTRK‐RSCNs and demonstrates the successful use of larotrectinib, a TRK inhibitor, in achieving both clinical and histological remission.