Non-Involuting Congenital Hepatic Hemangioma: Lessons from a Case Series.

: Congenital hepatic hemangiomas (CHHs) are typically considered rapidly involuting tumors, similar to their cutaneous counterparts (RICHs). However, non-involuting tumors remain poorly characterized. This study examines the evolutionary patterns and management strategies for non-involuting congenital hepatic hemangiomas (NICHHs). : We conducted a retrospective review of clinical, imaging, histological, and genetic data of children diagnosed with NICHH-defined as showing no signs of involution for at least 18 months-between 1991 and 2022. : Seven patients (five females, two males) were identified. The median age at diagnosis was 42 days (range: 0-1440). Five patients had asymptomatic lesions, predominantly located in the right hepatic lobe. Histologic confirmation was available in three cases, and a gene mutation was identified in one. The median follow-up period was 75 months (range: 35-191). Three patients with giant NICHH were treated with sirolimus, resulting in partial response in two cases and lesion stabilization in one. The four untreated patients showed diverse evolutionary patterns, including delayed involution and tardive growth. : NICHH lesions demonstrate distinct long-term evolution. Accurate diagnosis and regular monitoring are essential to avoid unnecessary interventions. Sirolimus may offer a promising non-surgical treatment for select patients, particularly those with giant lesions.