SUMMARY:We noted enlargement of the internal auditory canal in several of our patients with posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, eye abnormalities, and sternal or supraumbilical defects (PHACES) association and hence evaluated children with PHACES for the presence of an enlarged internal auditory canal and potential associated findings, including infantile hemangioma within the internal auditory canal, to understand the genesis of this enlargement. We reviewed our records to identify children with PHACES association who had been evaluated with MR imaging at our institutions. Imaging was reviewed for abnormal enhancement in the internal auditory canal, internal auditory canal enlargement, cerebellar hypoplasia, prominence of the petrous ridge, and deformity of the calvarium. We raise the possibility of an association between enlargement of the internal auditory canal in PHACES and a generalized malformation of the posterior fossa with cerebellar and calvarial hypoplasia.
ABBREVIATIONS:IAC ϭ internal auditory canal; PHACES ϭ posterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, eye abnormalities, and sternal or supraumbilical defects P osterior fossa malformations, hemangiomas, arterial anomalies, cardiac defects, eye abnormalities, and sternal or supraumbilical defects compose the PHACES association.1,2 The regional facial infantile hemangiomas of PHACES association are frequently associated with ipsilateral cerebellar hypoplasia and ipsilateral anomalies of the intracranial internal carotid artery. 3,4 More recently, attention has been drawn to the incidence of intracranial hemangiomas, especially in the internal auditory canal (IAC) and cerebellopontine angle cistern.5-8 The purpose of this study was to document the incidence and imaging appearance of anomalies of the IAC and the potential for associated posterior fossa anomalies in patients with PHACES association.
CASE SERIESThe index patient was a 25-year-old woman who presented with chronic hearing loss and a history of a facial hemangioma in infancy. Initial temporal bone CT revealed a funnel-shaped configuration of the prominent left IAC, prominence of the left posterior petrous ridge, hypoplasia of the left occipital bone, and findings consistent with a persistent left stapedial artery (Fig 1). Subsequent MR imaging demonstrated left cerebellar hypoplasia, enlargement of the left IAC, and an asymmetrically prominent left retrocerebellar CSF space (Fig 2). No abnormal enhancement was observed in the IAC or posterior fossa.Subsequent review of clinical data bases at 2 institutions identified 44 patients (37 male, 7 female) diagnosed with PHACES association who underwent diagnostic MR imaging of the brain between 2003 and 2012. Institutional review board approval was obtained from the 2 participating institutions for this retrospective review. A neuroradiologist with 9 years of experience and a pediatric neuroradiologist with 20 years of experience performed a consensus review of MR imag...