Immunoexpression of BAP1, ROS1, and ALK in Spitzoid Melanocytic Tumors.

Our study revealed 2 additional BAP1-inactived cases and described its respective frequency. The absence of anomalous expression of translocation-related proteins ALK and ROS1 in this series, composed predominantly of low-grade/low-risk tumors, indicates that translocated spitzoid lesions may not be as prevalent as initially suggested, at least in some populations. Furthermore, our findings encourage additional investigation on unequal occurrence of such immunomarkers among different diagnostic categories of spitzoid neoplasms.