NTRK1 and neoplasm: From the above-mentioned histological features [2], the tumor was suspected to harbor an NTRK1 fusion, and this was confirmed through an RNA-based next generation sequencing assay, which detected a 5′ partner of LMNA. Although rare melanomas harboring NTRK1 fusions exist, Spitz lineage more commonly portends indolent biologic behavior.