Epithelioid hemangioma (EH), also known as histiocytoid hemangioma, and angiolymphoid hyperplasia with eosinophilia, is a rare and benign vascular lesion [1],[2],[3],[4],[5],[6],[7],[8],[9],[10]. It most often occurs in the head and neck region, within the bone or soft tissue [1],[2],[5],[6],[7],[8],[9],[10]. These lesions tend to be small, usually not exceeding 10 cm [10]. Epithelioid hemangioma in children lacks comprehensive knowledge regarding clinical characteristics, outcomes, and consensus on treatment [7]. Complete removal of the lesion, via surgical excision, is the commonly reported treatment, making local recurrence rare [10]. However, treatment involving incomplete resection has a reported recurrent rate of approximately 33% [10].

We present a case of EH in a 2-year-old Asian male in the left frontal bone of the skull. Diagnostic and management challenges are discussed.

A previously healthy 2-year-old male presented with pneumonia. His workup revealed a bump on the left side of his head. He had no associated constitutional symptoms such as weight loss, fever, headaches, or seizures. He underwent imaging, including head and chest computed tomography (CT) and head magnetic resonance imaging (MRI). The latter revealed multiple ring-enhancing intra-axial lesions involving the gray-white matter junction of the bilateral frontal, left-sided parietal, left-sided occipital, and left-sided temporal lobes surrounded by significant vasogenic edema. The foci showed blooming artifact in the susceptibility weighted sequence (SWI) (Figure 1). The calvarium parietal bone showed the presence of multiple lytic intradiploic lesions associated with a soft tissue component (Figure 2). The skeletal survey did not reveal any lytic lesions. Abdominal ultrasound displayed an enlarged liver without focal lesions and no lymphadenopathy. The clinical considerations included inflammatory lesions, such as tuberculosis and fungal infection, and less likely multiple metastases. The patient is doing clinically well during follow-ups, and the MRI demonstrated improvements in intracranial lesions with no new parenchymal findings (Figure 1).

The lesion showed progressive growth during four months of follow-up; mandating a surgical resection of the lytic bony lesion with scalp soft component (Figure 3). Pathology revealed soft tissue and bone involvement with a vascular small- to medium-sized proliferation lined by endothelial cells with occasional cytoplasmic vacuolization (Figure 4). The intervening stroma showed marked reactive inflammatory cells infiltrating the background, with a predominance of eosinophils (Figure 4). Brisk mitotic activity and necrosis were not identified. Immunohistochemistry showed negative CD1a. The sarcoma panel molecular testing was negative for single-nucleotide variants (SNVs) and translocations. These findings are not commonly associated with malignant lesions, thus ruling out epithelioid hemangioendothelioma and angiosarcoma. After extensive investigation and discussion, the consensus opinion is that the morphological and immunohistochemical features seen in this skull bone lesions specimen are those of an EH. The patient underwent a comprehensive surgical resection aiming to remove the lesion. Interestingly, only one lesion was surgically excised, as the remaining lesions seem to be regressing spontaneously. The patient showed no signs of recurrence during the 12-month follow-up period.

In pediatric patients, EH occurs more frequently in males with a median age of 14.4 years [7]. Among adult populations; however, the literature reports a higher prevalence in women with a median age ranging from 20–50 years old and a mean onset of 30–33 years old [8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18]. Our current case involves a 2-year-old Vietnamese patient diagnosed with EH. Epithelioid hemangioma is most prevalent among Asian and Caucasian populations, a trend that aligns with our case, and is considered rare in elderly and non-Asian pediatric populations [10],[15],[17],[18].

Epithelioid hemangioma is commonly seen in the head and neck region in both pediatric and adult populations [1],[2],[4],[6],[7],[8],[10],[14],[15],[16],[17],[18],[19],[20],[21],[22], aligning with our case presentation in the left frontal bone of the skull. However, the location of EH lesions can vary throughout the body [5],[7],[8],[10] (Table 1 and Table 2).

Additionally, our patient displayed symptoms of lesion growth and pain, mirroring symptoms reported in other pediatric EH cases [2],[7],[11]. However, the commonly reported symptoms among other cases include pruritus and pain [19]. Imaging revealed multiple ring-enhancing intra-axial lesions located predominantly in the gray-white matter junction of bilateral frontal left-sided parietal, left-sided occipital, left-sided temporal lobes surrounded by significant vasogenic edema. Also, the calvarium showed multiple lytic diploic lesions predominantly on the left side of the calvarium and with soft tissue components. A skeletal survey revealed no other lytic lesions. Abdominal ultrasound showed an enlarged liver with no focal lesion, normal spleen, and no lymphadenopathy. Interestingly within the adult literature, only one case has been reported in a 66-year-old woman with primary EH affecting the central nervous system (CNS) and manifesting in the CNS [22].

Regarding the pediatric population, there is no current treatment consensus for EH due to its rarity [7],[10]. Pediatric cases of EH [1],[2],[3],[4],[5],[10], including the presented case, typically present as well-circumscribed lesions, allowing for feasible complete surgical excision, a pattern similarly observed in most adult lesions [13],[14],[17],[19]. In our case, the lesion was dissected freely from the bone—falling in line with the most common method of treatment for EH reported in both pediatric and adult populations [1],[2],[4],[6],[7],[8],[10],[14],[15],[16],[17],[18],[19],[20]. Surgical excision typically results in low morbidity and has been deemed the most successful treatment [1],[2],[4],[6],[8],[10]. Similarly, the literature reports complete excision with follow-up as the most effective treatment of EH in adults [14],[15],[16],[17],[18],[19],[20],[21],[22].

The rarity of EH within the pediatric population has contributed to the difficulty in the characterization of diagnoses, as highlighted in previous literature [3],[4],[7],[10]. Similarly, the adult literature also indicates a lack of therapeutic protocols for EH in the brain due to its infrequent occurrence [22]. Despite these challenges, our case aligns with the treatment and outcome consensus observed in pediatric cases of EH. Successful outcomes and no recurrence are evident post-treatment and follow-up, mirroring findings in the literature [6]. While some cases, both in pediatric and adult populations, have reported medical treatments involving propranolol, sirolimus, and steroids, the necessity for long-term follow-up is emphasized to ensure successful outcomes in patients undergoing such interventions [7],[8],[14],[15],[16].

Our patient experienced numerous back-to-back viral infections following surgical treatment. However, he is doing well with no recurrence of EH during the 12-month follow-up.

We report a rare case of EH in a 2-year-old male. Notably, our patient’s very young age, multifocal lesion distribution, and unexpected outcome with lesion involution during follow-up distinguish this case. Additionally, the novelty of intracranial involvement expands the understanding of EH beyond its typical presentation limited to the skull and scalp.