Abstract
Herein, we present the case of a previously healthy 54 year-old female who developed several weeks of unilateral tinnitus and aural fullness. She subsequently underwent unilateral pressure equalization tube placement at an outside institution after exam demonstrated a middle ear effusion, conductive hearing loss and normal nasopharyngoscopy. Ultimately, an MRI revealed an occult mass in the infratemporal fossa (ITF), which was successfully removed via an endoscopic transnasal ITF approach. Following resection of a histopathologically confirmed benign neurofibroma, she reported complete resolution of her symptoms. The antiquated diagnostic algorithm of unilateral effusion suggests that normal nasopharyngscopy successfully “rules out” a causative neoplastic process; however, Eustachian tube occlusion by occult skull base lesions may be missed without further investigation. This case highlights the need for additional radiological investigation of unexplained unilateral persistent middle ear effusion in the setting of normal nasopharyngoscopy.
1
Introduction
The traditional diagnostic algorithm for any patient presenting with persistent unilateral middle ear effusion dictates the need for nasopharyngoscopy to rule out a lesion compressing or infiltrating the Eustachian tube, and in the absence of an abnormal upper aerodigestive exam, a tympanostomy tube can be empirically placed for presumed idiopathic Eustachian tube (ET) dysfunction. However, this strategy only interrogates the membranous distal end of the ET and does not fully evaluate the infratemporal fossa, which houses the ET, and could therefore result in a considerable delay in diagnosis of an occult ITF or skull base mass. Herein we describe the case of a 54 year-old female who presented with unilateral middle ear effusion secondary to ET compression from an ITF neurofibroma and discuss diagnostic workup and management.
2
Case report
A 54 year-old, previously healthy woman presented with greater than a month long history of continuous non-pulsatile unilateral left-sided tinnitus, aural fullness and subjective hearing loss. Her primary care physician subsequently diagnosed her with unilateral middle ear effusion. However, secondary to worsening symptoms, the patient presented to the local Emergency Department, where a contrast enhanced MRI of the head and neck was obtained which revealed a 2.6 × 1.5 × 2.8 cm well-circumscribed, enhancing mass involving the left ITF, medial to the pterygoid musculature. This was thought to involve the third division of the trigeminal nerve ( Fig. 1 ). She reported no personal or family history of neurofibromatosis type 1 or 2, or history of neurogenic tumors. Differential diagnosis included schwannoma, neurofibroma, perineuroma, ganglioneuroma, or a malignant peripheral nerve sheath tumor . An outside otolaryngologist placed a pressure equalization tube in her left ear, which partially relieved her ear fullness but did not improve her tinnitus. The patient was subsequently referred to our clinic, one month following the initial onset of symptoms, and physical examination revealed a patent and functioning PE tube and a normal upper airway endoscopic exam. An audiogram demonstrated mild to moderate mixed hearing loss on the left side with a large volume type B tympanogram.
The patient was subsequently taken to the operating theater for a left extended endoscopic medial maxillectomy (EEMM) approach with ITF dissection and gross total resection of the mass using intraoperative image guidance ( Fig. 2 ). The tumor was found pedicled on a small branch of the mandibular nerve just medial to the medial pterygoid muscle. Pathology specimens were focally positive for S-100, neurofilament, and β-catenin, with a negative SMA, supporting the diagnosis of neurofibroma. The patient was kept overnight for observation and discharged the following day without complications. At her two-week follow-up, the patient incidentally reported complete resolution of her tinnitus and aural fullness. She did report mild paresthesias in the distribution of the maxillary nerve (V2) from her inferior left maxilla to her mandible including her upper lip and palate. Fortunately, these symptoms had almost completely resolved by her three-month follow-up appointment. At four months post-operatively she had a Sino-Nasal Outcome Test (SNOT-22) score of zero, demonstrating excellent nasal function . There was no evidence of tumor recurrence by MRI imaging at six months following surgery.
2
Case report
A 54 year-old, previously healthy woman presented with greater than a month long history of continuous non-pulsatile unilateral left-sided tinnitus, aural fullness and subjective hearing loss. Her primary care physician subsequently diagnosed her with unilateral middle ear effusion. However, secondary to worsening symptoms, the patient presented to the local Emergency Department, where a contrast enhanced MRI of the head and neck was obtained which revealed a 2.6 × 1.5 × 2.8 cm well-circumscribed, enhancing mass involving the left ITF, medial to the pterygoid musculature. This was thought to involve the third division of the trigeminal nerve ( Fig. 1 ). She reported no personal or family history of neurofibromatosis type 1 or 2, or history of neurogenic tumors. Differential diagnosis included schwannoma, neurofibroma, perineuroma, ganglioneuroma, or a malignant peripheral nerve sheath tumor . An outside otolaryngologist placed a pressure equalization tube in her left ear, which partially relieved her ear fullness but did not improve her tinnitus. The patient was subsequently referred to our clinic, one month following the initial onset of symptoms, and physical examination revealed a patent and functioning PE tube and a normal upper airway endoscopic exam. An audiogram demonstrated mild to moderate mixed hearing loss on the left side with a large volume type B tympanogram.
