Lesion Morphology in Multifocal Infantile Hemangiomas

Background/Objectives Multifocal infantile hemangiomas ( MIH s; previously called neonatal hemangiomatosis) can be associated with extracutaneous hemangiomas. We observed different morphologic types of hemangiomas in children with MIH s and sought to find out whether they are related to the clinical course. Methods This was a retrospective study of 103 infants with MIH s and a control group of 261 age‐matched patients with solitary focal infantile hemangiomas ( IH s) seen at an academic pediatric dermatology department between 2004 and 2014. Results Two morphologic subtypes of hemangiomas were identified: miliary focal hemangiomas ( MFH s; small, lens shaped) in 58 of 103 MIH patients (56.3%), and classical nonmiliary focal IH s ( NMIH s; larger, irregularly shaped) in 17 of 103 patients (16.5%). MIH s featuring both types (mixed type) were observed in 28 of 103 patients (27.2%). MFH lesions were significantly smaller (mean 5.3 mm [range 1–20 mm] vs 22.0 mm [range 2–100 mm]), more numerous (23.4 ± 27.3 [range 5–175] vs 7.4 ± 2.8 [range 5–15] p  <  0.001), and occurred up to an older age (6.0 ± 5.8 months [range 0–27 months] vs 3.8 ± 2.6 months [range 0–9 months]) than NMIH s. There was a weakly positive correlation between the number and presence of extracutaneous IH s in children with MFH s. Significantly more children with MIH s were delivered preterm than those with solitary IH s. Conclusions The number of IH s correlates inversely with their size. MFH s follow a clinical course different from that of classical IH s, are associated with prematurity, and may confer greater risk of extracutaneous hemangiomas. Miliary hemangiomas thus appear to present a separate IH subset requiring special attention.