Putting LUMBAR on Your Radar.

Infantile hemangiomas (IHs) are the most common vascular tumors in children. While many are uncomplicated, a significant minority can cause cutaneous complications or be associated with multiorgan congenital anomalies. Infants with so-called "segmental" IH (patterned and not round) are at-risk for two related syndromes: PHACE (posterior fossa anomalies, hemangioma of the head or neck, cerebrovascular arterial anomalies, cardiac and eye anomalies) and LUMBAR (IH of the lower body; urogenital anomalies and IH ulceration; spinal cord malformations; bony, anorectal, arterial, and renal anomalies). Prompt recognition of LUMBAR syndrome is crucial, given the potential for IH-associated complications, such as ulceration and permanent disfigurement, and more importantly, associated regional birth anomalies. This article synthesizes current knowledge on LUMBAR syndrome, including recognition, evaluation, diagnosis, risk factors, pathogenesis, and management. [Pediatr Ann. 2025;54(3):e112-e116.].