Non-Hodgkin Lymphoma Mimicking Vestibular Schwannoma

Abstract

Progressive unilateral hearing loss and an MRI are usually enough to diagnose vestibular schwannoma (VS). We were consulted by a 45-year-old man with otalgia and left-sided hearing loss as well as ipsilateral facial paralysis that had begun two weeks prior. Due to a possible atypical presentation of VS, an MRI was ordered, which revealed an intracanalicular lesion occupying the left cerebellopontine angle cistern. With no signs of systemic disease and considering the total left ear deafness, the patient underwent retrolabyrinthine mastoidectomy. During the procedure, a mass incompatible with VS was found and a biopsy was performed, which led to a diagnosis of non-Hodgkin's lymphoma (NHL). The patient was referred to an oncologist for treatment and, in time, achieved complete remission of the lesion. This case shows us that symptoms of VS may vary in tumor size and location and that atypical presentations warrant investigation. Non-Hodgkin's lymphoma (NHL), although not among the most common differential diagnoses, should be remembered due to its varied clinical presentation broadly dependent on its subtype and dissemination.

Keywords: central nervous system lymphoma; cerebellopontine angle tumor; internal auditory canal; non-hodgkin lymphoma (nhl); vestibular schwanomas.

Figure 1. Preoperative MRI on T1 showing an expansive lesion with enhancement after gadolinium administration located along the pathway of the left internal auditory canal and cerebellopontine angle, measuring approximately 1.4 cm on the laterolateral axis. The red arrow shows the tumor.

Figure 2. Intraoperative view via the retrolabyrinthine approach showing the lesion occupying the left internal auditory canal. The green arrow shows the tumor.

Figure 3. The figure shows that the tumor was highly positive for Ki67 (left image) and CD 20 (right image) with the hematoxylin and eosin (H&E) method (central image)