RESUMEN
We describe the case of a 28-year-old woman who presented with an acute dense left facial paralysis. Magnetic resonance imaging demonstrated enhancement of the labyrinthine portion of the facial nerve, and Bell's palsy was the presumed initial diagnosis. After 2 months without recovery despite receiving steroid and antiviral therapy, the patient underwent further workup. Computed tomographic scan demonstrated a mass lesion adjacent to the tympanic portion of the facial nerve, and electromyography showed active denervation and prominent fibrillation potentials. Surgical excision of the tumor was performed with decompression and sparing of the facial nerve. Histologically, the tumor proved to be an inflammatory pseudotumor (IPT). At the 3-year follow-up, the patient had an improvement in her facial nerve function, progressing to a House-Brackman grade III. An IPT can masquerade as Bell's palsy with sudden complete facial paralysis. Failure to obtain even slight recovery in Bell's palsy should prompt further workup, including appropriate imaging, to assess for a mass lesion. Confusion of an IPT with a nerve-based tumor on frozen section and imaging could lead to inappropriate resection and cable grafting of the facial nerve. Therefore, the relationship between an IPT and facial nerve paralysis is vital and must be recognized for treatment and to maximize postoperative facial nerve function.