Expression of β1 adrenergic receptor in vascular anomalies in children.

Objective Controversial, heterogeneous, and inconsistent responses to beta-blockers have been reported in some cases of infantile proliferative hemangiomas. On the basis of these clinical observations, we aimed to examine the β1 adrenergic receptor (β1-AR) protein expression distribution among different types of pediatric vascular anomalies. Methods Immunohistochemistry (IHC) was performed for β1-AR on 43 surgical specimens. Results We found positive β1-AR IHC staining in all intramuscular hemangiomas, capillary-lymphatic, lymphatic, venous, and combined malformations, and Masson's tumor cases, as well as in 7 of 10 cases of proliferative infantile hemangiomas. Conclusions Our research demonstrates, for the first time, the degree of heterogeneous expression of β1-AR among pediatric vascular malformations. Our results support the need for β1-AR assessment in pediatric vascular anomalies to select cases with a robust response to β1-selective blockers. β1-AR assessment may have a strong impact on therapeutic refinement for pediatric vascular anomalies by selecting cases with a stronger response to beta-blockers.