Unusually Large Patch-Type Noninvoluting Congenital Hemangioma of the Shoulder: A Report of Two Cases.

Noninvoluting congenital hemangiomas (NICHs) are vascular tumors that are fully formed at birth and do not regress. Clinically, NICHs persist indefinitely over time. Histologically they are characterized by deep dermal lobules of small vessels with endothelial cells that do not stain with glucose transporter 1 (GLUT1). Two similar cases of unusually large, patch-type NICHs of the shoulder in neonates were observed in the past 20years in two pediatric dermatology units in Italy. In both cases, histopathology showed lobular collections of small vessels that did not stain with GLUT1. The clinical features of the two cases remained unchanged over a follow-up period of 10 and 4years, respectively. The large size and flat appearance of the lesions could be due to their early onset during embryogenesis.