Malignant melanoma of the cerebello-pontine angle region

[Primary malignant melanoma of the central nervous system: A diagnostic challenge]

BACKGROUND

The rare incidence of primary malignant melanoma of the central nervous system and its ability to mimic other melanocytic tumors on images makes it a diagnostic challenge for the neurosurgeon.

CLINICAL CASE

A 51-year-old patient, with a tumor located in the right forniceal callosum area. Total surgical excision was performed. Histopathological result was consistent with the diagnosis of primary malignant melanoma of the central nervous system, after ruling out extra cranial and extra spinal melanocytic lesions.

CONCLUSIONS

The primary malignant melanoma of the central nervous system is extremely rare. There are features in magnetic resonance imaging that increase the diagnostic suspicion; nevertheless there are other tumors with more prevalence that share some of these features through image. Since there is not an established therapeutic standard its prognosis is discouraging.

Primary intracranial malignant melanoma: A rare casewith review of literature

We present a rare case of the primary intracranial melanoma in the right parafalcine frontal region in a 65-year-old male. Computed tomography and magnetic resonance imaging showed a Space occupying lesion in the right parafalcine frontal region with necrosis, vasogenic edema and mass effect. A rather well-defined, dark brown-black tumor was totally removed and histologically diagnosed as malignant melanoma. The patient improved after surgery. In our case, no systemic melanomas were found in close clinical examinations, there was a single nodular tumor attached to the leptomeninges and a favorable outcome was obtained by surgical treatment alone. Primary central nervous system melanomas have rarely been reported, and this case is reported for its rarity.

Bilateral Cerebellopontine Angle Metastatic Melanoma: A Case Report

Although melanoma accounts for approximately 1% of all malignancies, melanoma metastases to the cerebellopontine angles (CPAs) are exceedingly rare. Here we describe a patient with melanoma metastases to the internal auditory canals and CPAs who presented with a remote history of cutaneous melanoma. This patient had a rapidly progressive hearing loss, vestibulopathy, and facial nerve dysfunction. Magnetic resonance imaging demonstrated bilateral, enhancing CPA lesions but was otherwise nonspecific. The diagnosis required a careful history, unilateral surgical resection for tissue acquisition, and histopathologic confirmation. A search for primary cutaneous melanoma at the time of presentation was negative. However, the history of cutaneous melanoma 8 years earlier distinguishes this patient's metastatic disease from solitary primary intracranial melanoma, an equally rare disease. Treatment consists of surgical excision, radiation, chemotherapy, and immunotherapy. The prognosis for patients with melanoma metastases is generally poor, but isolated reports of long-term survival have been described. Metastatic disease to the CPAs must be included in the differential diagnosis for any patient presenting with rapid-onset VIIth or VIIIth cranial nerve symptoms.

CPA Melanoma

OBJECTIVE

Melanoma rarely invades the cerebellopontine angle (CPA) and can evade accurate diagnosis, which may alter management decisions. Diagnosis may be facilitated via careful history, magnetic resonance imaging (MRI) findings, and cerebrospinal fluid (CSF) analysis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Thirteen internal auditory canal/CPA lesions in eight patients who presented with CPA syndrome and who had a pathological diagnosis consistent with malignant melanoma. There were four bilateral and four unilateral lesions. Six of eight patients had a history of melanoma. One was apparently primary CPA lesion, whereas all others were metastatic.

INTERVENTION(S)

T1- and T2-weighted precontrast and postcontrast gadolinium-enhanced MRI were obtained, including fat suppression and fluid-attenuated inversion recovery sequence images in two patients; lumbar puncture with CSF centrifugation and cytological analysis confirmed the diagnosis in two patients. Translabyrinthine craniotomy was performed for tumor extirpation in five patients.

MAIN OUTCOME MEASURE(S)

Symptoms at presentation, MRI findings, presence of malignant cells in CSF, tumor progression, intraoperative findings, response to treatment, time interval from initial diagnosis of melanoma elsewhere, and survival.

RESULTS

Seven of eight patients had history and/or MRI findings suggestive of malignancy in the internal auditory canal and/or CPA, and diagnosis was confirmed via CSF analysis in two patients. In one patient, diagnosis was made at surgery.

CONCLUSION

Internal auditory canal melanoma portends a grim prognosis, can occur up to 17 years after initial melanoma diagnosis/treatment, and can be detected with appropriate MRI sequences, especially enhanced fluid-attenuated inversion recovery images. In disseminated cases, diagnosis can be confirmed with lumbar puncture demonstrating malignant cells. Management includes tumor resection when melanoma seems to be solitary and malignant cells are not present in CSF. Intrathecal chemotherapy and radiation are recommended for dissemination, although the survival rate is still poor.

Primary malignant melanoma of the cerebellopontine angle: a diagnostic dilemma: case report

OBJECTIVE

To present a rare case of a primary malignant melanoma of the central nervous system presenting as a cerebellopontine angle (CPA) tumor and to delineate aspects of the clinical presentation and magnetic resonance imaging scan characteristics that may suggest this unusual condition.

CLINICAL PRESENTATION

The clinical presentation consisted of a short duration of right-sided sensorineural hearing loss, facial weakness, and ataxia in a previously healthy man. Brain magnetic resonance imaging scans showed a right-sided CPA tumor exhibiting shortening of T1 and T2 relaxation times, but overall neuroradiological features were not consistent with any commonly occurring CPA tumors.

INTERVENTION

Gross total excision of the lesion was accomplished via a right suboccipital craniectomy. Histological examination revealed a malignant melanoma. A detailed search excluded extracranial primary melanoma.

CONCLUSION

Correlation of clinical and imaging findings offer the most important clues in the diagnosis of such unusual primary malignant tumors of the CPA. A history of rapid onset of audiovestibular symptoms, presence of facial palsy, and shortening of T1 and T2 relaxation times on magnetic resonance imaging scans should arouse the clinician's suspicions.

Primary Melanocytic Tumor of the Cerebellopontine Angle Mimickinga Vestibular Schwannoma

OBJECTIVE

The majority of tumors of the cerebellopontine angle (CPA) are benign. We report the case of a primary malignant melanoma of the CPA that mimicked a vestibular schwannoma (acoustic neuroma). We discuss the differential diagnosis and prognosis of melanotic lesions at this location.

CLINICAL PRESENTATION

A 49-year-old man presented with a 7-year history of unilateral deafness and a several month history of imbalance, intractable nausea and vomiting, as well as weight loss. A neurological work-up revealed a large tumor in the left CPA radiographically diagnosed as a vestibular schwannoma.

INTERVENTION

A translabyrinthine approach revealed a pigmented, vascular neoplasm encasing vessels and cranial nerves of the left CPA. The tumor was subtotally resected, and a histopathological diagnosis of melanoma was made. The patient had no history of cutaneous melanoma and no other site of disease was ever discovered.

CONCLUSION

This case most likely represents primary melanoma of the central nervous system that mimicked a vestibular schwannoma. The differential diagnosis of melanotic lesions of the CPA is discussed as are the prognostic implications of each diagnosis.

Primary malignant melanoma of the cerebellopontine angle

BACKGROUND

Malignant tumors of the cerebellopontine angle are very rare, accounting for less than 1% of lesions at this site. These may be primary or secondary tumors of the temporal bone, central nervous system (CNS), or leptomeninges. Malignant melanoma is uncommon, accounting for 1.5% of all types of malignant tumors. Metastatic melanoma is a frequent cause of CNS metastasis, often with leptomeningeal spread. Primary leptomeningeal melanoma is, however, rare and even more so at the cerebellopontine angle. The prognosis for CNS malignant melanoma is generally very poor.

PATIENT

The authors describe the case of a 29-year-old woman with unilateral hearing loss and facial paresis. Magnetic resonance imaging (MRI) demonstrated a mass that was thought to be an acoustic neuroma but was seen to involve the cochlea as well as the internal auditory meatus and cerebellopontine angle. The lesion was subsequently excised completely by a trans-labyrinthine approach, with facial nerve preservation, and was shown on histologic examination to be a malignant melanoma. Further comprehensive investigation did not reveal a primary extracranial site or any sign of CNS spread. The clinical features of this case, including the radiologic and histologic findings, are described, and literature concerning management is reviewed.

Cerebellopontine angle metastasis from clear-cell renal carcinoma presenting as bleeding from the ear

Metastatic lesions in the cerebellopontine angle are rare. We encountered one such metastatic lesion from clear-cell renal carcinoma that had a striking clinical appearance, bleeding from the ear and multiple lower cranial nerves' involvement. While the overall prognosis in CNS metastasis from systemic malignancy is gloomy, useful palliation can be achieved in patients with solitary lesions.