Apocrine Hidrocystoma Masquerading as a Posttraumatic Cerebrospinal Fluid Leak<subtitle>Case Report and Literature Review</subtitle>

Abstract

Otolaryngologists frequently care for patients with injuries that violate multiple aspects of the facial skeleton and skull base. Cerebrospinal fluid (CSF) leak is a common complication after skull base trauma. Two percent of head injuries and 12% to 30% of all basilar skull fractures result in CSF leak. 1 In a retrospective review 2 of 820 fractured temporal bones, 122 CSF fistulae were noted. Posttraumatic CSF leaks originate most commonly from frontal or ethmoid sinus fractures or appear after longitudinal temporal bone fracture. 3 Typically,CSFleakpresentsasclearnasaldrainageormeningitis.Wedescribeacaseofswelling in the midface under a radial forearm fasciocutaneous free flap that was used to reconstruct the palate, midface, and skull base. Initial evaluation of this painless, slow induration 1 year after enucleation of orbital remnants was highly suspicious for a skull base CSF leak, mucocele, or encephalocele. Surgical exploration and final pathologic analysis revealed an unusual presentation of a dermatologic entity: apocrine hidrocystoma.