Massive spinal epidural infantile hemangioma, image findings, and treatment: a case report and review of literature

Infantile hemangiomas are hamartomatous lesions that result from proliferations of vascular endothelial cells [1]. They are estimated to affect approximately 4% of infants, most commonly found in the skin, and typically regress without surgical treatment [2, 3]. In contrast, the prevalence of neuraxial involvement by infantile hemangioma is low comprising around 1% of all hemangiomas. When present, neuraxial hemangiomas have the propensity to involve the extradural spine [4] and, in contrast to cutaneous hemangiomas, both surgical and medical management have been proposed in the literature. However, the classification and nomenclature used to describe endothelial malformations has been a source of confusion with variable adoption of the terminology suggested by the International Society for the Study of Vascular Anomalies (ISSVA). This is especially true when describing CNS vascular lesions in the pediatric population [5]. Moreover, sometimes it might be difficult to separate infantile hemangiomas from other vascular tumors and vascular malformations based on histology alone requiring more reliance on the clinical picture. This makes the literature about the subject somewhat confusing with possible misuse of the term hemangioma, making a proper evaluation of the prevalence, clinical course, image characteristic (including tumor location), histology, and treatment difficult [5‐7]. Herein, we present a case of a massive infantile epidural hemangioma in a neonate, showing multilevel foraminal extensions and successfully treated with only beta-blockers as we discuss the clinical, MR, CT, US, and histological features of this lesion aiming to clear up some of the confusion about the subject.

A 3-week-old female neonate presented to the neurosurgery team for evaluation for lower extremities weakness. On history taking, the patient was born at full term with a birth weight of 3.145 kg to a healthy mother. The mother had received Enoxaparin for antiphospholipid syndrome during her pregnancy with no other complications. The baby was born by cesarean section due to breach position. On physical examination, the patient was noticed to have a prolapsed anus, a midline lumbar dimple, negative deep tendon reflexes, presence of primitive reflexes, distal paresis of the right leg with flaccid deformity, proximal distal paresis of the left leg and laxity of the anal sphincter.

An MRI of the brain and spine was done (Fig. 1) revealing a large infiltrative avidly enhancing tumor occupying the spinal canal from T10 to S1 (8 vertebral levels) for a craniocaudal distance of 8.3 cm with extra spinal components infiltrating and protruding from multiple expanded neural foramina bilaterally (Dumble chapped) and abutting the psoas muscles with involvement of some adjacent paraspinal muscles. The mass showed high signal intensity on T2-weighted images, low signal intensity on T1-weighted images and extensive flow voids suggesting a vascular component. There was no evidence of microscopic or macroscopic fat on fat-suppression and in-phase and out-of-phase sequences. Increase in T2 signal was noted in the bilateral psoas muscles, more significantly on the left, which could be related to muscle edema secondary to denervation changes. The spinal cord was obliterated at the level of the lesion. No signal abnormality was detected at the rest of the spinal cord.

Contrast-enhanced CT images (Fig. 2) showed a high attenuation mass expanding the spinal canal and neural foramina. No calcifications were seen. Non-fusion of the posterior elements from L4 caudally was noted in keeping with spina bifida. The differential diagnosis included neuroblastoma, plexiform neurofibroma, schwannoma and hemangioma.

An ultrasound-guided core biopsy (Fig. 3) of this mass was done showing hypoechoic protruding masses with high vascularity on Doppler images. The specimen was sent for histological analysis.

Histologic examination of the specimen (Fig. 4) showed lobular proliferation of capillary sized vascular spaces that are lined by bland endothelial cells with some areas of focal intravascular thrombosis. The findings were described as typical for capillary hemangioma.

The decision was made to not proceed with surgical excision at such a young age due to the high risk of complete paralysis. The patient was started on Propranolol 15 mg two times a day for 6 months, until the next radiologic examination.

Follow-up MRI in 6 months (Fig. 5) showed significant decrease in size of the mass, with residual posterior epidural component, significant decrease of the foraminal extension however still present from T12-L1 to L3-L4, and resolution of the cord compression. There was no myelomalacia. The mass still exhibits intense enhancement however there is significant decrease in the internal flow voids suggesting progressive involution (involution phase). The original images showing extensive vascularity suggest a proliferative phase. Clinically the patient showed improvement in the left lower extremity motor power.

The clinical behavior of the tumor, along with the imaging and histological features were consistent with infantile hemangioma.

The ISSVA classifies vascular anomalies into 2 major categories based on clinical and cellular behavior: 1. vascular tumors such as hemangiomas, which arise by endothelial hyperplasia. 2. vascular malformation, defined as a congenital or developmental morphogenic anomaly of various vessels with a normal endothelial turnover and normal growth rate [8]. Hemangiomas are divided into infantile or congenital hemangiomas with the previously known capillary, capillary/cavernous, and strawberry hemangiomas now categorized as “infantile hemangiomas” [4, 9, 10]. However the term capillary hemangioma seems, in some instances, to be used interchangeably by pathologists for infantile hemangioma and congenital hemangiomas [11].

Vascular malformations have been subdivided into two subgroups: slow- or low-flow malformations, and fast- or high-flow malformations. Low-flow include capillary, venous, lymphatic, and mixed malformations. The ISSVA classification has abandoned the terminology of cavernous hemangiomas (or cavernous malformations), instead the terminology of venous malformation is now used. However, it was not completely accepted by neurosurgeons; the term “cavernous malformation” is still used, and other terminologies that includes “cavernous” (e.g., cavernous hemangioma or cavernous angioma) are also used [7].

Regardless, infantile hemangioma might not be diagnosed by relying solely on pathology. The clinical history, classically presenting as a lesion appearing in the first few weeks of life, with the proliferative phase then reaching a plateau followed by a slow involuting phase, in addition to the imaging findings can be an integral elements of the diagnosis [12]. Moreover, immunohistochemistry and genetic studies may not be available for detailed pathological assessment. Therefore, confidently deciding to categorize a lesion based on histology alone might not be possible.

Epidural hemangiomas can present clinically with progressive myelopathy. The prevalence of epidural hemangiomas in the pediatric population is unknown with neuraxial involvement reported to compromise around 1% of all hemangiomas [4]. Of the 1454 patients listed with infantile hemangioma reviewed by Viswanathan V et al. (2009), 15 (1.0%) had involvement of the CNS, 6 (0.4%) of those were intraspinal, all of with epidural in location [4]. Cohorts by Drolet BA et al. (2010) showed a prevalence of 50% (21 cases) of “intraspinal” hemangiomas in patient with infantile hemangioma of the lumbosacral skin (n = 41) without specifying the specific spinal location (epidural, intradural or medullary) [13]. This study suggests that the prevalence of epidural hemangiomas in the pediatric population might be under-estimated, moreover not specifying the exact location of the hemangioma suggest difficulty in pinpointing the precise site relative to the spinal canal. This issue is especially relevant with large infiltrative masses. Schumacher WE et al. (2011) showed a prevalence of 45% (9 cases) of intraspinal hemangioma in patients with spinal dysraphism (n = 20). These were characterized as only extradural, present in six children, or only intradural, present in one patient with two children having both intra- and extradural hemangiomas [14].

Infantile hemangiomas are endothelial tumors rarely involving the spine. The classification and nomenclature used to describe vascular lesions has been a source of confusion with interchangeable use of various terminology and variability between the radiologist, pathologist, and neurosurgeon. Due to the clinical implications and different aggressiveness of the treatment options, proper diagnosis of intraspinal/epidural infantile hemangioma is key. Clinical history of a neonatal vascular lesion with a proliferative and involuting phase, supported by radiological features of enhancing intra-spinal mass with flow voids, sometimes in association with an extra-spinal component, should hint toward the diagnosis of an infantile hemangioma. Histological evaluation with GLUT 1 and LeY immunostaining is strongly recommended for the purpose of reaching a conclusive diagnosis, since this has a drastic effect on the management, perhaps making beta blockers, a very accessible medication, a first line therapy. Finally, both surgical and medical treatments should be considered with further research on the subject is needed.