Melanomas of the Cerebello-pontine angle

Timothy C. Hain, MD Page last modified: June 18, 2009

Melanomas are a rare tumor that can cause hearing decline and vertigo.

Melanoma's make up about 5 to 8% of all malignancies. They mainly affect the skin but they can also arise or be metastatic to the area of the ear. Metastases can occur as long as 17 years after removal of a cutaneous melanoma ! (Brackman and Doherty, 2007).

Diagnosis:

Factors suggesting the diagnosis are a history of melanoma, MRI findings and a cerebellopontine angle syndrome with rapid progression of symptoms (Oluigbo et al, 2006; Brackman and Doherty, 2007).

Metastatic melanoma's usually present with bilateral findings (Tu et al, 1994; Brackman and Doherty, 2007).

There are two MRI patterns. Pigmented melanoma's are hyperintense on T1, similar to a lipoma, but do not decrease as normal in signal with fat suppression sequences, and is hypointense or isointense on T2. They enhance with contrast.

Nonpigmented melomas are isointense on T1 and variable on T2, and enhance with contrast, resembling an acoustic neuroma (Piedra et al, 2006).

The diagnosis of metastatic melanoma can be confirmed via lumbar puncture.

Prognosis:

The prognosis of metastatic melanoma is poor because in this case there are tumor cells throughout the coverings of the brain (Arriaga, 1995). As of 2007, median survival time was about 12 months (Brackman and Doherty, 2007).

Primary melanoma can be treated surgically with more success.

References:

• Arriaga, M. A., W. W. Lo, et al. (1995). "Metastatic melanoma to the cerebellopontine angle. Clinical and imaging characteristics." Arch Otolaryngol Head Neck Surg 121(9): 1052-6.
• Brackmann, D. E. and J. K. Doherty (2007). "CPA melanoma: diagnosis and management." Otol Neurotol 28(4): 529-37.
• Oluigbo, C. O., S. R. Cooke, et al. (2006). "Primary malignant melanoma of the cerebellopontine angle: a diagnostic dilemma: case report." Neurosurgery 59(6): E1336; discussion E1336.
• Piedra, M. P., B. W. Scheithauer, et al. (2006). "Primary melanocytic tumor of the cerebellopontine angle mimicking a vestibular schwannoma: case report." Neurosurgery 59(1): E206; discussion E206.
• Tu, A. S., H. Wang, et al. (1994). "Bilateral involvement of the cerebellopontine angles by malignant melanoma metastasis: a case report." Md Med J 43(11): 967-70.