MINNEAPOLIS — Guidelines call for spinal, pelvic, and renal imaging to confirm a diagnosis of LUMBAR syndrome, but a recently published systematic review found that all patients with LUMBAR syndrome had a segmental infantile hemangioma that involved the midline, prompting a theory that no further workup is needed without this feature.

“We now need prospective confirmation, but our study suggests that children with lateral infantile hemangioma of the lower body but no midline involvement are unlikely to have accompanying LUMBAR syndrome,” reported Denise Metry, MD, pediatric dermatologist affiliated with Driscoll Children’s Hospital in Corpus Christi, Texas.

LUMBAR is an acronym for lower body hemangioma, urogenital anomalies, spinal cord malformations, and bony, anorectal, arterial, and renal anomalies. Just 2 years ago, diagnostic criteria developed by Delphi consensus were published in The Journal of Pediatrics.

At the time that the diagnostic criteria were published, there was still uncertainty about which clinical features of lower body infantile hemangiomas posed the greatest risk for LUMBAR syndrome and its complications, according to Metry, who led the expert panel that developed the 2024 guidelines.

The current systematic review was performed on 141 published and seven unpublished cases of LUMBAR syndrome that were used by a Delphi expert panel to develop the diagnostic criteria, according to Metry, who presented the findings as a poster at the Society for Pediatric Dermatology (SPD) 2026 Annual Meeting.

Of these cases, 91 were accompanied by photographs adequate to allow the hemangiomas to be evaluated for morphology and location, including whether the lesion involved the anatomic midline. For example, in cases of infantile hemangiomas located on the buttocks, involvement of the anatomic midline indicates that the hemangioma crossed the gluteal cleft to involve both buttocks (transmedian) or abutted the gluteal cleft (paramedian).

In this systematic review, all of the infantile hemangiomas were segmental (none were “partial segmental” or localized), all hemangiomas involved the midline, and all but one were transmedian, crossing the midline. The one exception was paramedian, meaning that it hugged the midline but did not cross it.

“No patients with LUMBAR syndrome had a strictly lateral hemangioma without any midline involvement,” Metry said. These results were published earlier this year in Pediatric Dermatology.

Even though this was a retrospective analysis based on a limited series of cases, it is also a substantial case series for a rare disorder. Although the findings cannot be confirmed in this study alone, it does suggest at the very least that infantile hemangiomas sparing the midline likely have a low risk for LUMBAR syndrome, according to Metry.

In the paper, Metry and her coauthors contrasted LUMBAR syndrome with PHACE, an acronym for posterior fossa malformations, hemangiomas of the cervicofacial region, arterial anomalies, cardiac anomalies, eye anomalies, and sternal or abdominal clefting. Although these are also often associated with serious systemic complications, they differ in embryogenesis.

Specifically, infantile hemangiomas associated with LUMBAR arise from midline embryologic structures, such as paraxial mesoderm and cloacal membrane, which also participate in the formation of the vertebral column, spinal cord, pelvis, and urogenital tract, according to Metry.

When disruptions in these fields develop, they can account for both the hemangioma and the accompanying congenital anomalies that characterize LUMBAR.

In contrast, infantile hemangiomas in PHACE syndrome “often occur in lateralized craniofacial segments, such as the temporal or auricular/periauricular regions,” Metry and her coauthors wrote in the published paper. In embryogenesis, the infantile hemangiomas follow neural crest migration patterns that do not cross the midline.

This embryologic difference explains why PHACE-associated hemangiomas “may respect lateral boundaries, while LUMBAR-associated lesions show strict midline involvement,” they hypothesized.

As this is a retrospective review, the risk for publication or selection bias that led to the observation cannot be ruled out, Metry acknowledged, but she explained that the 2024 diagnostic criteria are considered a starting point for collecting cases and consolidating research efforts.

The lack of diagnostic criteria before 2024, for example, likely explains why there is more clinical and genetic research for PHACE, which is also believed to be more common, she said.

In the 2024 diagnostic criteria paper, a LUMBAR diagnosis was based on the presence of a lower body, segmental infantile hemangioma in the lumbosacral, sacrococcygeal, and/or pelvic cutaneous regions accompanied by at least one additional specific criterion involving the urogenital, spinal cord, anorectal, skeletal, arterial, or renal systems.

With more cases identified by these criteria, the opportunity to confirm the hypothesis of midline involvement is expected to increase along with efforts to identify features with prognostic importance, according to Metry.

Metry reported having no potential conflicts of interest. 

Ted Bosworth, a career medical writer based in New York City, has been covering advances in clinical medicine, including dermatology and oncology, for several decades.