Net-like Superficial Vascular Malformation in a 5-Year-Old Girl: A Case Report With Clinicopathological Correlation...

Targetoid hemosiderotic hemangiomas (THH) are rare, benign vascular malformations believed to have a lymphatic origin. Recently, a novel entity called "net-like superficial vascular malformation" (NLSVM) has been reported, sharing many clinicopathological features with THH. We describe a case involving a healthy 5-year-old girl who presented with a vascular lesion above the left gluteus. The lesion, which first appeared at around 1 year of age, was asymptomatic but showed intermittent hemorrhagic changes and lacked a distinct targetoid appearance. Histological examination revealed a dermal vascular proliferation lined by a uniform and prominent single layer of endothelial cells with hobnail cytomorphology. Immunohistochemistry demonstrated strong, diffuse CD31 positivity, patchy and weak CD34 and D2-40 expression, and negativity for Wilms tumor 1 and glucose transporter isoform 1. Based on these findings, a diagnosis of NLSVM was established. Considering the benign nature of the lesion, the family opted against surgical resection, and the patient is currently under follow-up. This case illustrates that although NLSVM shares some overlapping features with classic THH, it remains a distinct entity and underscores the need for further research to elucidate its specific etiopathogenic, diagnostic, and prognostic characteristics.