Diameter Threshold for Screening LUMBAR Syndrome in Infants With Lumbosacral, Sacrococcygeal, Perineal, and Gluteal Infantile Hemangiomas: A Prospective Multicenter Cohort Study

Infantile hemangiomas located in the lumbosacral, sacrococcygeal, perineal, gluteal, or lower-limb-extending regions may be associated with LUMBAR syndrome. LUMBAR syndrome refers to a spectrum of regional congenital anomalies associated with lower-body infantile hemangiomas, including lower-body hemangioma, urogenital anomalies, ulceration, myelopathy or spinal dysraphism, bony deformities, anorectal malformations, arterial anomalies, and renal anomalies.

However, the optimal lesion size threshold for initiating systematic screening remains unclear. In current clinical practice, some patients with large or segmental hemangiomas undergo magnetic resonance imaging and systemic evaluation, whereas others with smaller but potentially high-risk lesions may not be screened. Therefore, a clinically practical and evidence-based diameter threshold is needed to guide LUMBAR syndrome screening.

Previous prospective evidence has suggested that lumbosacral infantile hemangiomas larger than 2.5 cm may be associated with a high rate of spinal anomalies. However, whether this 2.5-cm threshold applies to hemangiomas involving the sacrococcygeal, perineal, gluteal, or lower-limb-extending regions remains uncertain. Therefore, this study aims to prospectively evaluate the relationship between maximal lesion diameter and LUMBAR-associated anomalies and to identify an optimal screening threshold.