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Capillary hemangiomas are common benign vascular tumors in infants who often present with skin lesions on the face, neck, and thorax.⁶ Their occurrence in the central nervous system is a rare and challenging phenomenon because of their initial proliferative phase, which causes enlargement of the lesion, with a growth peak at 6 months after birth and the theoretical possibility of spontaneous regression.^5,6 This regression is typically observed at 4 years of age (30% of patients) and 7 years of age (80% of patients).¹¹ In our literature search, only case reports and small case series on intracranial capillary hemangiomas were found, and no uniform treatment was administered in the described cases. Surgery was performed in certain cases, whereas other cases involved clinical observation and/or treatment with steroids, thalidomide, bevacizumab, and/or temozolomide.^3,4,13,25

A different scenario is applicable for cutaneous hemangiomas.^12,15,24 In particular, for such tumors, propranolol has been the first-line treatment since Léauté-Labrèze et al.¹⁰ published a case series in 2008 that described severe infantile hemangiomas treated with this beta-blocker with excellent outcomes. To date, propranolol has not been described as a treatment for intracranial capillary hemangiomas. In this paper, we describe the first case in which an intracranial fetal capillary hemangioma has been successfully treated with propranolol.

Case Report

Discussion

On patient admission in the described case, we considered a teratoid/rhabdoid tumor or a medulloblastoma as possible etiologies. However, fetal tumors are rare in the posterior fossa and are generally associated with high mortality rates;¹ moreover, these tumors lack the high vascularity observed in this case. Given the intense vascularization of the tumor, a simple stereotactic biopsy could have led to a catastrophic hemorrhage. Thus, the patient was treated without pathological confirmation. In-depth analyses of the radiological findings, including high vascularity, excluded a teratoid/rhabdoid tumor and a medulloblastoma and suggested the possibility of a capillary hemangioma, which is a highly vascular lesion that is rare in the intracranial compartment but extremely common in the skin.

Capillary hemangiomas—also known as infantile hemangiomas, strawberry birthmarks, or hemangiomas—are benign vascular tumors characterized by an encapsulated mass that is lobular in shape with a poorly defined capillary channel consisting of a single layer of flattened endothelium without intervening brain parenchyma.^8,9,11,14 These tumors typically affect the skin and the soft tissues of the face, scalp, back, or chest in children,^2,6,8,14 appearing as a single lesion in 80% of cases.^9,11 Their reported frequency in neonates ranges from 0.05% to 5%.^8,11 Although superficial hemangiomas are common, intracranial capillary hemangiomas are rare, and few cases of definite, probable, or possible¹⁶ congenital intracranial capillary hemangiomas have been described in the literature; published cases are listed in Table 1.^{2,3,6–9,21–23}

Intracranial capillary hemangiomas can present as asymptomatic lesions or result in cranial nerve palsy, head circumference enlargement, and elevated intracranial pressure. In addition, these lesions are frequently associated with skin hemangiomas. Only 5 of 22 reviewed cases of intracranial capillary hemangiomas did not involve an associated skin hemangioma. Moreover, intracranial hemangiomas appear to be associated with PHACE syndrome^7,23 and exhibit a female predominance (with a male/female ratio of 1:2).^8,11 Capillary hemangiomas are also characterized by a proliferative phase during the 1st months of life that is followed by spontaneous regression in most cases.^5,18

Intracranial capillary hemangiomas are characterized by isointensity or hypointensity on T1-weighted MR images, with avid uniform contrast enhancement, and by hyperintensity on T2-weighted MR images. Because capillary hemangiomas present sinusoidal vascularization, the repetition of T1-weighted MRI at a different time with Gd could show a progressive enhancement differing from that observed with other posterior fossa tumors, which do not maintain this enhancement over time. On CT scans, these tumors are characterized by isodensity to hyperdensity, a lobulated morphology, and intense contrast enhancement. Although angiography is rarely performed, such studies of these tumors reveal enlarged arterial feeders and intense contrast staining, with pooling of the contrast medium within tumoral vascular spaces.^2,13,21,23 Doppler US of intracranial capillary hemangiomas indicates numerous intralesional and perilesional vessels, with a high-peak arterial Doppler shift.²³ The aforementioned imaging findings are not exclusive to intracranial capillary hemangiomas; in fact, these tumors must primarily be differentiated from meningiomas, hemangiopericytomas, and hemangioblastomas.

To date, as indicated in Table 1, no consensus exists regarding the treatment of intracranial capillary hemangiomas. In particular, the various therapies for these tumors include surgical removal, systemic steroid therapy, thalidomide, intralesional triamcinolone, bevacizumab, temozolomide, interferon, and clinical observation.^{2,3,6–9,21–23,25} The same variations in treatment were observed for capillary hemangiomas in the skin until 2008, when Léauté-Labrèze et al.¹⁰ described 11 patients with complicated infantile hemangiomas who were treated with propranolol and exhibited dramatic lesion regression within a short time period with minimal adverse effects. Subsequently, many authors began to examine propranolol and its role in capillary hemangioma treatment and have suggested this beta-blocker as a first-line treatment for severe infantile capillary hemangiomas.^12,15,24

Propranolol is a nonselective beta-adrenergic receptor antagonist that appears to promote vasoconstriction in capillary hemangiomas, reducing blood flow within these lesions and causing skin capillary hemangiomas to change color and soften. This beta-blocker appears to inhibit angiogenesis by decreasing the expression of proangiogenic growth factors, such as vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), most likely by inactivating the extracellular signal–related kinase/mitogen-activated protein kinase (ERK/MAPK) cascade. Another potential underlying mechanism of propranolol’s antiangiogenic effects is its reduction of matrix metalloproteinase-9 (MMP-9) expression, which leads to the inhibition of endothelial cell tubulogenesis.^18,20 Moreover, propranolol promotes the induction of apoptosis in capillary endothelial cells by blocking apoptosis inhibition by beta-adrenergic agonists (mediated by MAPK and the caspase cascade) and thereby increasing apoptosis rates.^17,18

Ghosh and Ghosh⁴ reported the use of propranolol in a 6-week-old female infant with cutaneous and intraspinal-extradural capillary hemangiomas, who exhibited an excellent response. Strahle et al.¹⁹ suggested the theoretical possibility of using propranolol to treat intracranial capillary hemangiomas based on the evident success of propranolol treatment for skin lesions and the occurrence of fewer adverse effects from propranolol treatment relative to steroid, thalidomide, bevacizumab, and temozolomide therapies. The most frequent side effects of propranolol use are low blood pressure, bradycardia, bronchospasm, and hypoglycemia. Although capillary hemangiomas can spontaneously regress, when the tumor mass compresses brain tissue (such as in the brain-stem, as detailed in the described case), treatment must be provided to relieve this compression because spontaneous total regression could take a long time. Surgical removal can be life-threatening given the intense vascularization of these tumors as well as a patient’s low weight and young age. Given this consideration and the knowledge that propranolol could cause the regression of capillary hemangiomas during the proliferative phase, we began to administer propranolol to a neonate with a giant, life-threatening intracranial capillary hemangioma. Our treatment produced subtotal regression by the 6-month follow-up and total regression by the 1-year follow-up, and the treated patient exhibited normal cognitive and motor development.