All cases of cutaneous cellular EH (n=16) showed strong diffuse immunohistochemical expression of FOS-B, in conjunction with positivity for ERG and nestin.
On the basis of a novel FOS-LMNA gene fusion identified by RNA sequencing in an index case of a skeletal EH with typical morphology, we sought to investigate the prevalence of FOS rearrangement in a large cohort of EHs.
Our work reveals that FOS stimulates endothelial sprouting and that perturbation of normal FOS degradation could account for the abnormal vessel growth typical of epithelioid hemangioma.