Lipochoristomas of the cerebellopontine angle and internal acoustic meatus: a seven-case review

Evaluating the utility of a scoring system for lipomas of the cerebellopontine angle

BACKGROUND

Cerebellopontine angle (CPA) lipomas are rare, benign, slow-growing masses. Resections are considered in symptomatic patients who are refractory to targeted medical therapies, but at those stages the lipomas have often reached considerable sizes and encompass critical neurovascular structures. The objective of this study is to develop and to evaluate the utility of a scoring system for CPA lipomas. The hypothesis is that CPA lipomas with lower scores are probably best managed with early surgery.

METHODS

The PubMed database was searched using relevant terms. Data on patient and lipoma characteristics were extracted and used to design a scoring system. CPA lipomas were stratified by scores with corresponding managements and outcomes analyzed.

RESULTS

One hundred and seventeen patients with CPA lipomas were identified and 40 CPA lipomas were scored. The remaining CPA lipomas were deficient in data and not scored. No lipomas were scored as 1. Score 2 lipomas (n = 12; 30%) most often underwent serial surveillances (n = 5; 41.6%), with the majority of symptoms remaining unimproved (n = 2; 40%). Patients with score 2 CPA lipomas treated with medical therapies (n = 3; 25%) often experienced symptom resolution (n = 2; 66.6%) (p = 0.0499). Patients with score 2 CPA lipomas undergoing surgical resections (n = 3; 25%) all experienced symptom resolution (n = 3; 100%) (p = 0.0499). Score 3 was most common (n = 16; 40%) and these lipomas were often surgically resected (n = 10; 62.5%). The majority of patients with score 3 CPA lipomas having undergone surgical resections (n = 10; 62.5%) experienced symptom improvement (n = 1; 10%) or resolution (n = 4; 40%).

CONCLUSIONS

Score 2 CPA lipomas are smaller and would be deemed non-surgical in general practice. However, our data suggest that these lipomas may benefit from either medical therapies or early surgical resections. The advantages of early surgery are maximal resection, decreased surgical morbidity, and improved symptom relief.

Meningeal carcinomatosis of the internal auditory meatus: clinical and imagery-aided differentiation

OBJECTIVES

To describe difficulties in diagnosing meningeal carcinomatosis of the internal auditory meatus (IAM-MC).

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary skull base surgery referral center.

PATIENTS

A series of six cases of patients diagnosed with IAM-CM over 14 years.

RESULTS

The primary cancer was known before diagnosis in three cases (adenocarcinoma of lung, breast, and melanoma). In two others, it was discovered at workup (lung, ethmoid adenocarcinoma). In the last case, no primary cancer was identified. Vestibular symptoms were the first complaint in five of the six cases. Referral symptom was facial paralysis in five cases and rapid-onset total deafness associated with severe unsteadiness in one. Rapid hearing decrease and symptoms of bilateralization were observed in five cases. Diagnosis was ascertained by discovery of malignant cells in the CSF in three cases and at tumor biopsy in one case. In the two other cases, the association of brain metastases and increased dura mater infiltration was convincing. Treatment consisted in radiation therapy to the whole brain in five cases and intrathecal chemotherapy in one case. Evolution was rapidly lethal in five cases. The last died free of disease 4 years after treatment.

CONCLUSION

IAM-MC is difficult to demonstrate. Progressive facial paralysis associated with aggressive and rapidly bilateral cochlear and vestibular symptoms are highly evocative in the event of cancer in the patient's history. If there is no history of cancer, lumbar puncture is to be repeated until malignant cells are discovered in the CSF before beginning radiotherapy.

CT and MR Imaging Characteristics of Intravestibular and Cerebellopontine Angle Lipoma

Intracranial lipoma is an uncommon entity. A rare type of tumor in the internal auditory canal (IAC) and the cerebellopontine angle (CPA) is lipoma. There are a few case reports in the literature related to intravestibular lipoma. Herein, we report a case of lipomas within the cerebellopontine angle and vestibule of the inner ear in a patient with tinnitus and dizziness. The patient was evaluated with a 1.5 T magnetic resonance imaging (MRI) system. MRI and CT showed the masses in the left CPA and the left IAC. These lesions were hyperintense on both T1- and T2 weighted images and showed no enhancement after gadolinium administration. Conservative management was suggested. Histopathological diagnosis is rarely necessary with the widespread use of magnetic resonance imaging. Considering significant morbidity during resection, conservative follow-up is the best approach for CPA and IAC lipoma.