Enlargement of the Internal Auditory Canal and Associated Posterior Fossa Anomalies in PHACES Association

How we approach hemangiomas in infants

Pediatric oncologists are increasingly involved in the management of benign vascular tumors and their associated life-threatening complications. Hemangiomas are the most common referring diagnosis to multidisciplinary vascular anomalies clinics. However, as contemporary research has revealed, hemangiomas are not a single, easily defined entity but rather a diverse set of related vascular tumors, each having a unique natural history, growth pattern, and response to therapy. This manuscript seeks to illustrate how we evaluate and manage these complex tumors, their complications, and associated syndromes, while remaining ever vigilant for malignant hemangioma mimickers such as soft tissue sarcomas and congenital leukemia.

Pediatric tinnitus: The role of neuroimaging

Tinnitus is defined as the perception of sound without an external source and can be categorized as either pulsatile or nonpulsatile (ie, continuous). A variety of etiologies have been reported to cause pediatric tinnitus, many with long-lasting implications due to hearing and concentration impairments. Therefore, imaging can be an essential part of the accurate and timely diagnosis of treatable etiologies. We describe neuroimaging findings in different etiologies of pediatric tinnitus. Etiologies of pulsatile tinnitus are frequently vascular in nature and include vascular loops, congenital vascular anomalies or variants, high riding jugular bulbs with or without a jugular bulb diverticulum, idiopathic intracranial hypertension, aneurysms, internal auditory canal hemangiomas, and petrous apex cephaloceles. Etiologies of continuous tinnitus frequently affect the middle/inner ear structures and include vestibular schwannomas, cholesteatomas, trauma, Chiari malformations, and labyrinthitis ossificans. CT and MR are often complementary modalities: CT is better suited to evaluate the integrity of the temporal osseous structures and MR is better suited to evaluate the vestibulocochlear nerve and to assess for the presence of any masses or malformations. Prompt diagnosis of the etiology of tinnitus in pediatric patients is important to avoid any potential long-term developmental impairments. In the approach to pediatric tinnitus, categorizing the symptoms as either pulsatile versus nonpulsatile and then being aware of the possible causes and imaging findings of either can assist both the clinician and the radiologist in making an expeditious diagnosis.

Hearing loss in PHACE syndrome: clinical and radiologic findings

PURPOSE

To characterize the types of hearing loss, auditory-related imaging findings, and hemangioma characteristics in patients with Posterior fossa malformations, Hemangiomas, Arterial anomalies, Cardiac defects, and abnormalities of the Eye (PHACE) syndrome.

METHODS

Retrospective medical records, audiologic data, and imaging review of all patients presenting to a tertiary care children's hospital with a proven diagnosis of PHACE syndrome from 2005 to 2016.

RESULTS

Twelve patients were identified with hearing and imaging data. 5/12 had hearing loss, 1 had unilateral severe sensorineural loss with minor conductive component, 1 had unilateral moderate sensorineural loss with minor conductive component, 1 had mild bilateral conductive loss, 1 had bilateral hearing loss (left severe mixed and right severe sensorineural), and 1 had moderate bilateral conductive loss. All patients passed their newborn hearing screening. Of the 5 patients with hearing loss, 3 had IAC hemangiomas (1 bilateral), 3 had enlarged IACs with prominent posterior petrous bones (1 bilateral), 2 had dysgenesis of the cerebellar vermis and hemispheres, there was 1 patient each with a deformed pinna and middle ear and mastoid effusions, and 1 patient had no abnormal auditory-related imaging findings. Patients with hearing loss were more likely to have more areas of cutaneous hemangioma involvement (mean 6.4 vs 3.1, p = .05). Laterality of hearing impairment correlated with the side of cutaneous hemangioma in all patients with hearing loss. Treatment with systemic propranolol did not improve hearing.

CONCLUSIONS

Patients with PHACE are at risk for hearing loss and may demonstrate radiologic abnormalities within the ear structures, although the type of hearing loss, imaging findings, and their respective correlation vary. While our results are limited by our small sample size, comprehensive audiology evaluations (as opposed to newborn screening testing only) should be considered for PHACE patients who have extensive cutaneous hemangioma or auditory-related imaging abnormalities, such as internal auditory canal hemangiomas.

Asymmetric Meckel Cave Enlargement: A Potential Marker of PHACES Syndrome

BACKGROUND AND PURPOSE

PHACES syndrome is a complex of morphologic abnormalities of unknown cause and includes posterior fossa abnormalities; head and neck infantile hemangiomas; arterial, cardiac, and eye anomalies; and sternal or abdominal wall defects. Accurate identification of the syndrome is important for optimal treatment. The purpose of this study was to investigate the incidence of asymmetric Meckel cave enlargement, a potential novel imaging marker, in a population of patients referred for evaluation of possible PHACES syndrome.

MATERIALS AND METHODS

Eighty-five patients referred for neuroimaging evaluation of possible PHACES syndrome were identified and stratified on the basis of their ultimate clinical PHACES diagnosis categorization into PHACES, possible PHACES, or not PHACES. MR imaging studies were subsequently reviewed for the presence or absence of unilateral Meckel cave enlargement, with the reviewer blinded to the ultimate PHACES syndrome categorization.

RESULTS

Twenty-five of 85 patients (29%) were ultimately categorized as having PHACES or possible PHACES according to consensus guidelines. Asymmetric Meckel cave enlargement was present in 76% (19/25) of these patients and in 82% (19/23) of only those patients with definite PHACES. This finding was present in none of the 60 patients determined not to have PHACES syndrome. In 7/19 patients (37%) with this finding, subtle MR imaging abnormalities consistent with PHACES were missed on the initial MR imaging interpretation.

CONCLUSIONS

Asymmetric Meckel cave enlargement was a common feature of patients with PHACES in our cohort and may serve as a novel imaging marker. Increased awareness of this imaging feature has the potential to increase the diagnostic accuracy of PHACES.