gms | German Medical Science

Objective: The most common lesions in the cerebellopontine angle (CPA) are vestibular schwannoma (70-80%) and meningioma (5-10%) followed by epidermoid cysts (6-7 %). The goal of this study is to analyze the surgical management of an extremely rare lesion of the CPA - the meningeal melanocytoma. The annual incidence of meningeal melanocytoma of the CNS has been estimated as 1 per 10 million persons. We present three cases of primary CPA melanocytoma (PCPAM), which have been treated, in our department. Particular attention was paid to their clinical presentation, surgical treatment, early and late treatment outcomes, and recurrence rates.

Methods: Patients who received surgical treatment for PCPAM from January 2004 to October 2016 were identified by a computer search of their files from the Department of Neurosurgery, Tübingen. We identified three patients with PCPAM, which were surgically treated in our Department in the last 12 years. Two were male and one was a female patient, aging 33, 45 and 54 years (mean age: 44 years). The 45-year-old male patient had two previous surgeries elsewhere. Patients were evaluated for initial symptoms, pre- and postoperative facial nerve function, pre- and postoperative cochlear function, complications and recurrence rate by reviewing surgical reports, patient documents, neuroradiological data, and follow-up data. In all cases the PCPAM was confirmed histologically. In one patient it was a melanocytoma with intermediate grade.

Results: There was no mortality in this series. Anatomical facial and cochlear nerve preservation were achieved in all 3 cases. One patient had a new moderate facial palsy after surgery (H+B II). The cochlear nerve funtion was not significantly affected by surgery. Two patients had adjuvant radiotherapy (50,4 Gy and 54 Gy) and one patient had ion beam therapy for tumor recurrence (six years after surgery). All patients presented tumor recurrence at 2 years, at 3 years and at 6 years follow up respectively.

Conclusion: Our case series include a very heterogenous patient collective (one case of intermediate grade melanocytoma, one case of multifocal recurrence after two previous surgeries in other hospitals), however preservation of the facial and cochlear function was achieved in all cases. At long-term follow-up all patients had recurrence. Treatment must include besides surgery radiotherapy in order to avoid early recurrence.