Intrameatal Tumours Presenting as a Hearing Disturbance: Case Reports of Meningioma and Lymphoma

Abstract

This paper presents two patients with chronic progressive hearing disturbance. Each patients had an intrameatal tumour, part of which extended to the cerebellopontine (CP) angle. In both cases, the patients were initially diagnosed with an acoustic neurinoma. A 63-year-old male experienced a hearing disturbance in the left ear for 1.5 years prior to visiting our hospital. Magnetic resonance (MR) imaging revealed a mass which was surgically resected. The tumour originated from the intrameatal dura mater. Histologically, the tumour was a meningioma. Similarly, a 53-year-old male presented with systemic lymphoma diagnosed 10 months earlier, and a hearing disturbance in the right ear that began 3 months prior to visiting our hospital. MR imaging prior to chemotherapy revealed a mass which extended to the CP angle. Part of the tumour in the CP angle disappeared after chemotherapy, suggesting a secondary lymphoma. Another tumour appeared later in Meckel's cave on the left side; however, it decreased in size following repeated chemotherapy. The present results indicate that differential diagnosis of intrameatal tumours and acoustic neurinomas may be difficult due to the small tumour size. Recent progress in neuroradiology may allow distinction of intrameatal tumours as a separate tumour classification. Our second patient is the sixth reported case of a CP angle lymphoma in the literature.

Meningiomas of the Internal Auditory Canal

“…Some authors opted for a subtotal tumor removal in order to preserve the facial nerve 14,15,22,27 . Among the cases reported in literature, 12.2% presented a transient facial palsy 18,21,23,27,33,36 and 26.5% a permanent facial palsy. 7,11,13,20,22,24,25,31,33 However, an actual comparison between our results and the cases reviewed would be very difficult because most articles either present a limited number of patients or do not use a facial palsy classification.…”

“…In the cases reviewed, where facial postoperative function was described, more than 50% presented a “normal” facial nerve 6–8,11–12,15–27,31,33–34,36 . Some authors opted for a subtotal tumor removal in order to preserve the facial nerve 14,15,22,27 .…”

“…In literature, hearing preserving techniques were used in more than 50% of the patients, despite many patients having suffered from preoperative anacusis or unserviceable HL. Among the remaining patients with preoperative class A to C hearing, fewer than 63% maintained hearing 8,16,18,20,22–24,27,28,30,33,34 . It is thus imperative to decide the appropriate approach, considering the importance of an adequate tumor removal over the confined possibilities of hearing preservation with surgery.…”

“…Among the remaining patients with preoperative class A to C hearing, fewer than 63% maintained hearing. 8,16,18,20,[22][23][24]27,28,30,33,34 It is thus imperative to decide the appropriate approach, considering the importance of an adequate tumor removal over the confined possibilities of hearing preservation with surgery. Moreover, most of the patients (10 of 12) ceased to complain tinnitus after surgery.…”

“…There have been less than 50 cases of pure ICMs described in literature and nearly 100 IAC meningiomas extending partly in the CPA (largest series are collected in Table I). 6–8,11–36 …”