Segmental lower body infantile hemangiomas are important to recognize and follow closely, as these are well known to accompany multiple other congenital anomalies. They have a possible female predominance and no known etiologies or risk factors.

LUMBAR is the acronym for Lower body hemangioma, Urogenital abnormalities / ulceration, Myelopathy, Bony deformities, Anorectal malformations / arterial anomalies, and Rectal anomalies. This association has previously been described as SACRAL (Spinal dysraphism, Anogenital, Cutaneous, Renal and urologic anomalies associated with an Angioma of the Lumbosacral region) and PELVIS (Perineal hemangioma, External genital malformations, Lipomyelomeningocele, Vesicorenal abnormalities, Imperforate anus, and Skin tag). LUMBAR is currently considered the preferred nomenclature.

Lower body infantile hemangioma and cutaneous defects: Segmental type infantile hemangiomas are larger (> 5 cm) and may correspond to neuroectodermal placodes. Of cutaneous defects, ulceration is found to be most common, with other defects including lipoma, acrochordon, caudal appendix, nevus, and sacral dimple. Of note, ulceration may occur in diaper region secondary to irritation. Congenital anomalies bear an association with the region affected by infantile hemangiomas. Lumbar infantile hemangiomas were found to be correlated with myelopathy with two or more congenital midline skin lesions, such as lipoma, being a strong indicator of the presence of an anomaly. Sacral infantile hemangiomas were correlated with urogenital and renal anomalies as well as anorectal malformations.

Urogenital: Anomalies vary widely including, but not limited to, bladder extrophy, pyelo-ureteral duplication, and ambiguous genitals.

Myelopathy: This is the most common congenital anomaly found in LUMBAR syndrome. This may include tethered spinal cord, lipomyelocele, and lipomyelomeningoceles. Other abnormalities include syrinx formation and abnormal termination of conus medullaris.

Bony abnormalities: Includes deformity of the foot, leg length discrepancy, hip dysplasia, sacrum abnormality, and scoliosis.

Anorectal: Imperforate anus is most commonly found. Other abnormalities include fistulas, anterior displacement, and stenosis of the anus, as well as deviated gluteal cleft.

Arterial: Dysplasia and narrowing have been found to be most common; however, noninvolution of embryonic anastomoses and altered vascular course or origin were found as well.

Renal: Absence of a kidney most commonly found. Other abnormalities include hydronephrosis, pelviectasis, and incomplete ascension (pelvic kidney).