Pediatric internal auditory canal cavernous hemangioma with rapid progression of sensorineural hearing loss: illustrative case

Abstract

BACKGROUND

Cavernous hemangioma of the internal auditory canal is extremely rare and is characterized by symptoms such as vertigo, sensorineural hearing loss, and facial nerve dysfunction.

OBSERVATIONS

A health examination on an 11-year-old female in the fifth grade revealed hearing loss in the left ear. She also had dizziness that had persisted for approximately 1 year. Pure-tone audiometry revealed sensorineural hearing loss in her left ear. Rightward horizontal and rotatory nystagmus was detected. Facial paralysis was not present. Magnetic resonance imaging showed a lesion that was suspected to be hemangioma. The authors selected a left suboccipital retrosigmoid approach. The tumor showed a berry-tufted appearance throughout the cerebellopontine angle. The seventh cranial nerve penetrated the tumor and partly circulated outside the tumor with marked adhesion. The authors partially resected the tumor to avoid damaging the facial nerve. A histological examination identified cavernous hemangioma.

LESSONS

The fundamental treatment for cavernous hemangioma of the internal auditory canal is complete surgical removal; however, any surgical intervention may result in hearing loss and facial paralysis. The extent of surgery needs to be decided intraoperatively based on the balance between preoperative symptoms and postoperative complications.

Cavernous hemangiomas, which are known as cavernous malformations (angiomas) or cavernomas, are vascular malformations in the central nervous system. The prevalence of cavernous hemangioma is estimated to be 0.4%–0.9% in the general population.^1,2 Approximately one-fourth of cavernous hemangiomas are detected in pediatric patients.^3–5 Cavernous hemangiomas occur as a sporadic or familial autosomal dominant disorder that is linked to 3 genes: cerebral cavernous malformation 1 (CCM1; KRIT1), CCM2 (MGC4607), and CCM3 (PDCD10).⁶ In addition to arteriovenous malformation and moyamoya disease, vein of Galen aneurysmal malformations, pial arteriovenous fistula, and dual arteriovenous fistula are differential diagnoses of cerebrovascular lesions in pediatric patients and may cause cerebral hemorrhage and focal neurological deficits.⁷

Cavernous hemangiomas in the internal auditory canal (IAC) are extremely rare and are characterized by symptoms such as dizziness, vertigo, sensorineural hearing loss, tinnitus, facial paralysis, and facial hemispasm.⁸ Initial symptoms are often similar to those of conditions affecting the inner ear, such as Meniere’s disease, idiopathic sudden sensorineural hearing loss, and perilymphatic fistula.^9–11 Cavernous hemangioma of the IAC also needs to be differentiated from vestibular schwannoma, facial schwannoma, and meningioma, even if magnetic resonance imaging (MRI) is performed.¹² We herein report a pediatric case of cavernous hemangioma of the IAC with rapid progression of sensorineural hearing loss and vertigo.

Illustrative Case

An 11-year-old female was referred to Yokosuka Kyosai Hospital with hearing loss in the left ear. It had been identified for the first time when she was in the fifth grade. She also had dizziness that had persisted for approximately 1 year. There was no family history of hearing loss or cavernous hemangioma. Pure-tone audiometry revealed sensorineural hearing loss in the left ear but not in the right ear (Fig. 1A). Rightward horizontal and rotatory nystagmus was observed. Facial paralysis was not observed. Three weeks later, her hearing deteriorated and rightward nystagmus persisted (Fig. 1B). MRI was performed because the left IAC was dilated on computed tomography (CT; Fig. 2A). Calcification was not evident within the lesion. MRI showed a lesion that was suspected to be a hemangioma based on a heterogeneous and mainly hypointense signal on T1-weighted images, an isointense signal on T2-weighted images, and contrast-enhanced T1-weighted images (Fig. 2B–D). The tumor was hypovascular on angiography (Fig. 3A). We recommended tumor removal because of the deterioration of hearing in the left ear. Hearing loss progressed to deafness 1 month after the angiography (Fig. 1C); however, facial paralysis was not present. We selected a left suboccipital retrosigmoid approach. The tumor had a berry-tufted appearance throughout the cerebellopontine angle, and the eighth cranial nerve was not identified (Fig. 3B). The tumor strongly adhered to the brainstem. Since it was not possible to perform normal internal decompression, the tumor was cauterized and decreased in size. The seventh cranial nerve penetrated the tumor and partly circulated outside the tumor with marked adhesion. Since frozen pathology revealed a nonneoplastic lesion, the tumor was partially resected to avoid damaging the facial nerve. A histological examination identified cavernous hemangioma. We continue to monitor her symptoms, with persistent deafness in the left ear and no facial nerve paralysis being noted at the 1-year follow-up.

FIG. 1.

Pure-tone audiometry before surgery: first visit (A), second visit 3 weeks after the first visit (B), and third hearing test the day before surgery (C).

FIG. 2.

The left IAC was dilated on CT (A). MRI showed a lesion that was suspected to be hemangioma based on a heterogeneous and mainly hypointense signal on T1-weighted images (B), an isointense signal on T2-weighted images (C), and contrast-enhanced T1-weighted images (D).

FIG. 3.

A: The tumor was hypovascular on angiography. B: The tumor had a berry-tufted appearance.

Discussion

Observations

We herein present the first pediatric case of cavernous hemangioma of the IAC with the rapid progression of sensorineural hearing loss and vertigo. Based on a literature search, 54 cases of cavernous hemangioma of the IAC have been reported to date, and all were in adults.¹³

The most commonly reported symptom was hearing loss. Zhu et al.¹³ reported that the majority of patients had hearing loss. The present case also exhibited rapid progression of hearing loss to deafness. The second most common symptom was facial nerve paralysis or facial spasm, which occurred in 51.8% of the cases. Vestibular symptoms were noted in 11.1% (6 of 54). The present case also had dizziness with nystagmus.

The fundamental treatment of cavernous hemangioma of the IAC is complete surgical removal to reduce the risk of tumor bleeding; however, the surgical complications of hearing loss and facial paralysis may be inevitable. On the other hand, stereotactic radiotherapy is considered for cases in which surgery is difficult. Although stereotactic radiotherapy does not reduce the size of the tumor, it contributes to reductions in the bleeding rate and is considered to be an effective treatment method.^14,15 There are currently no case reports on the outcome of stereotactic radiotherapy for cavernous hemangioma of the IAC. Therefore, the effects of radiosurgery on the facial nerve and hearing are unknown.

Tumors may adhere to adjacent nerves because cavernous hemangioma of the IAC arises from the vascular spaces of the cranial nerves or dural surfaces.^16,17 Zhu et al.¹³ reported successful hearing preservation after surgery in only 4 of 54 patients. These 4 patients had small tumors that did not adhere to or strongly compress the nerves.^18–21 After surgery, most patients showed deterioration in hearing loss or deafness. On the other hand, facial nerve preservation is controversial. Surgical complications related to facial nerves were more variable, with some patients showing improvements and others exhibiting the deterioration of paralysis. Therefore, Zhu et al. recommended surgery if the patient already has facial nerve paralysis and a close follow-up of facial symptoms along with images until the tumor shows additional changes.

Cavernous hemangiomas occur as a sporadic or familial autosomal dominant disorder. The familial form is linked to CCM1, CCM2, and CCM3. In Japanese cases, 55.6% of patients have the familial form with these mutations, while 62.5% of isolated cases showed CCM mutations.²² Stahl et al.²³ detected these mutations in 67% of isolated cases. Furthermore, 75% of isolated cases had the familial form in a systematic analysis of a French cohort.²⁴ Although the present case was sporadic and had no family history of cavernous hemangioma, she and her family may be a familial case.

In pediatric cerebrovascular lesions, vein of Galen aneurysmal malformations and pial arteriovenous fistula may be differentiated from each other. However, they often develop with hydrocephalus, heart failure, an enlarged head circumference, and convulsions in neonates or childhood and may cause focal neurological deficits, headache, and subarachnoid hemorrhage as the patient ages.^7,25 Therefore, these diseases were ruled out because the patient in the present case was 11 years old, which was older than previous cases, did not exhibit similar symptoms, and the lesion was not an aneurysm. Moyamoya disease and dual arteriovenous fistula were also ruled out based on imaging findings and angiography. Since the tumor was in the IAC, vestibular schwannoma and meningioma were included in the differential diagnosis in addition to hemangioma.

Based on presurgical examinations of the present case, we planned to preserve the facial nerve but not the eighth cranial nerve. The patient and her family also strongly requested efforts to avoid facial paralysis before surgery. Although we planned to perform coil embolization to suppress intraoperative bleeding on angiography, it was not necessary because the tumor was hypovascular. We partially resected the tumor to preserve the facial nerve due to marked adhesion. Since the tumor remains, the patient is being followed up due to the risk of the re-enlargement of the tumor and bleeding. Once bleeding or facial paralysis occurs, it may be necessary to sacrifice the facial nerve and perform total resection of the tumor. Alternatively, to avoid complete facial paralysis, stereotactic radiotherapy may be conducted instead of surgery to reduce bleeding. It currently remains unclear whether stereotactic radiotherapy prevents facial paralysis. MRI at the 1-year follow-up showed no regrowth of the tumor.

Lessons

Cavernous hemangioma of the IAC is extremely rare in pediatric patients and is characterized by symptoms such as vertigo, sensorineural hearing loss, tinnitus, and facial nerve paralysis. When a tumor in the IAC is identified in pediatric patients, not only vestibular schwannoma, facial schwannoma, and meningioma but also aneurysmal malformations and arteriovenous fistula need to be differentiated, particularly when cavernous hemangioma is suspected. The fundamental treatment for cavernous hemangioma of the IAC is complete surgical removal; however, any surgical intervention may result in hearing loss and facial paralysis. Therefore, the extent of surgery needs to be decided intraoperatively based on the balance between preoperative symptoms and postoperative complications.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: all authors. Acquisition of data: Hyakusoku, Tanaka. Analysis and interpretation of data: Hyakusoku, Tanaka. Drafting of the article: Hyakusoku, Tanaka. Critically revising the article: Tanaka. Reviewed submitted version of the manuscript: Hyakusoku, Tanaka. Approved the final version of the manuscript on behalf of all authors: Hyakusoku. Statistical analysis: Hyakusoku, Tanaka. Administrative/technical/material support: Hyakusoku, Tanaka. Study supervision: Tanaka.