Article ID: 2021.01066
Infantile hemangioma (IH) is a common benign tumor during infancy, although the detailed mechanism behind it has not been fully elucidated. Based on previous studies, we hypothesized that formation of hemangioma might be triggered by secondary physiological events (perinatal hypoxia or mechanical stress during delivery) in patients carrying germline risk mutations. We aimed to clarify the mechanism by evaluating whether head and neck lesions were more frequent in patients in who IH appeared after birth compared with those in who it was present at birth. Clinical data of 62 lesions in 51 patients with IH were collected. All patients were analyzed for correlation of onset with gender, localization, family histories, gestational age, birth weight, and clinical subtypes. Distribution of lesions on the head and neck was slightly more frequent in the after-birth IH group, compared with those with IH present at birth, but without significant difference (47.6% vs. 40.0%, p = 0.32). On the other hand, the ratio of superficial and deep type IH at birth was significantly altered compared with that in IH after birth (19:0 vs. 26:7, p = 0.039). In addition, IHs appearing after birth tended to more commonly have multiple lesions than those with IH present at birth, with statistically significant difference (25.8% vs. 0%, p = 0.0164). There may therefore be different triggers for IHs at birth and IH after birth. Further studies with greater number of patients are necessary to validate these findings.