###### Abstract
melanocytic tumors; melanocytic nevi; melanocytomas; genomic alterations +
Footnote †: journal: Medical  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Tumor Type** & **Genomic Alteration** & **Histologic Findings** & **Molecular Testing** \\ \hline \multirow{6}{*}{_ALK_ fusions} & _HRAS_ mutations and/or 11p & Predominantly intradermal with desmoplastic & NGS, FISH, SNP \\  & amplifications & stroma; large melanocytes [1,2] & microarray, CGH [3] \\ \cline{2-3}  & & Plexiform architecture; non-pigmented & \\  & melanocytes with pericellular clefts; can show & \\  & cytologic atypia and increased mitotic & NGS, FISH [3] \\  & activity [4, 5, 6, 7] & \\ \hline \multirow{6}{*}{_ROS1 fusions_} & _Prominent junctional melanocytic nests with trans-epidermal elimination and adnexal involvement; sometimes angiomatoid Spitz; can show cytologic atypia [8]_ & NGS, FISH [3] \\ \cline{2-3}  & _Thin elongated_rete ridges; frequent Kamino & \\ \cline{2-3}  & _NTRKI_ fusions & bodies; rosette-like structures; extreme maturation; often associated with lymphocytic infiltrate [4, 6, 9, 10] & NGS, FISH [3] \\ \cline{2-3}  & _NTRK3::MYO5A_ fusions & _Spindled melanocytes; fascicular to plexiform growth pattern; palisading and rosette-like structures [11]_ & NGS, FISH [3] \\ \cline{2-3}  & _NTRK3::ETV6_ fusions & _Epithelial melanocytes with abundant eosinophil and distinct cell borders; pleomorphic nuclei; large coalescing nests [7, 11]_ & NGS, FISH [3] \\ \cline{2-3}  & _NTRK3::MYH9_ fusions & _Large epithelial melanocytes; syncytial growth with central desmoplastic stroma and peripheral collagen trapping [11]_ & NGS, FISH [3] \\ \cline{2-3}  & _MET_ fusions & _Large nests of intermediate to large epithelioid to spindled melanocytes; pericellular clerfs; epidermal hyperplasia [12]_ & NGS, FISH [3] \\ \cline{2-3}  & _RET_ fusions & _Large nests of small to intermediate-sized, monotonous epithelial, discheusive melanocytes [13, 14]_ & NGS, FISH [3] \\ \cline{2-3}  & _BRAF_ fusions & _Superficial cellular sheet-like dermal component; less cellular base with prominent desmoplastic reaction; no maturation; large epithelioid melanocytes; can show severe cytologic atypia; increased mitotic figures [4, 9, 15, 16, 17, 18]_ & NGS, FISH [3] \\ \cline{2-3}  & _MAP3K8_ fusions and mutations & _Asymmetric, nodular, or dome-shaped; epidermal hyperplasia; nested junctional component; no maturation; epithelial melanocytes with large uniform nuclei and prominent nucleoli; multinucleated giant melanocytes; can show severe cytologic atypia; increased mitotic figures; ulceration [9, 19, 20, 21, 22, 23]_ & NGS, FISH [3] \\ \hline \multirow{6}{*}{_MAP2K1_ mutations} & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelioid melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2-3}  & _MAP2K1_ mutations & _Wedge-shaped; overlapping features with deep penetrating and dysplastic nevi; plexiform growth pattern; tendency to converge around the adnexal structures and neurovascular bundles; melanin pigment pigment accumulation in stroma and melanophages; poor maturation; large epithelial melanocytes; can show severe cytologic atypia [21, 24, 25, 26]_ & NGS [3] \\ \cline{1-1} \cline{2