Primary Intracranial Malignant Melanoma with Extracranial Metastasis

Primary Malignant Meningeal Melanoma Complicated by Cerebral Venous Sinus Thrombosis: An Illustrative Case With a Systematic Review of the Literature

Melanocytic tumors of the central nervous system (CNS) such as meningeal melanoma are exceedingly rare tumours derived from leptomeningeal melanocytes. We report an illustrative case of a previously healthy 47-year-old male who presented with tonic-clonic seizure. Magnetic resonance imaging (MRI) with contrast demonstrated a homogenously enhancing right temporal extra-axial lesion. The patient was stabilized on anti-epileptic medications and dexamethasone prior to proceeding with complete surgical resection of the lesion. Intraoperatively, the lesion was heavily pigmented with invasion of the surrounding dura and skull. Histopathology revealed a poorly differentiated neoplasm with nuclear atypia and melanin-containing cells with strong SOX10 and variable S100 positivity. Computed tomography (CT) of the chest, abdomen, and pelvis showed no metastatic disease, and molecular profiling was negative including absent BRAF mutation. He began checkpoint inhibitor therapy and subsequently developed cerebral venous sinus thrombosis managed with anticoagulation. Sixteen months post-operatively, he was neurologically intact, working full-time, and had resumed immunotherapy. We systematically reviewed the literature on primary intracranial malignant melanoma (PIMM) with the goal of understanding the prognosis and best treatment options for this disease. Our systematic review produced 82 articles (118 unique cases) of PIMM. The average age at diagnosis was 45.9 years (95% CI:42.9-48.9), and headache (54.2%) was the most common initial presentation. Eighty-nine percent of patients had primary surgical resection, and 41.0% of these individuals experienced a recurrence with a mean time to recurrence of 19.6 months (95% CI:6.95-32.23). Adjuvant therapy was administered in 65.7% of surgically resected patients; including radiotherapy, chemotherapy, immunotherapy, or a combination. In summary, PIMM is a rare tumour that can appear radiographically similar to meningioma. The results of our systematic review demonstrate that surgical resection remains the mainstay of therapy for best long-term prognosis.

Primary intracranial melanoma, amelanotic variant: Case report

Primary brain melanoma is a very rare tumour (only 0.07% of primary CNS neoplasms) which usually shows with abundant melanin content; whereas hypo/melanotic variants have been scarcely described. We introduce the case of a female patient with headache, left brachial paresis and frontallobar syndrome. The MRI image showed a right frontal mass with homogeneous contrast uptake. As treatment, a complete surgical resection was performed. Pathology was diagnostic for melanoma, with very low melanin content and a high proliferative index. A thorough extension study was performed to rule out an extracranial primary origin. Due to several intercurrent complications, the patient evolved unfavorably, not being able to receive further treatment. The amelanotic variant of primary intracranial malignant melanomas has not been described in detail previously. We will review the literature, focusing on the particularities of management and diagnosis of this clinical entity.

Melanoma of the central nervous system: A report of three cases

Melanomas within the Central Nervous System (CNS) are most commonly metastatic lesions, with primary melanomas comprising only 0.05-0.07% of all brain tumors. We report three cases of primary CNS melanoma. The patients were young adults. There were two females and one male. On preoperative investigations, two cases were misdiagnosed to be angiomas on Magnetic Resonance Imaging (MRI). The melanotic nature of the lesion was an intraoperative observation. Pathologic examination showed features of malignancy with invasion of tumor cells into the brain parenchyma. In two patients, presence of systemic lesions were ruled out after surgery by whole-body Positron Emission Tomography (PET) scan. These patients were subject to adjuvant radiotherapy, while one patient succumbed immediately post-surgery. Primary CNS melanomas are rare with no defined treatment protocols. Histopathology diagnosis is crucial to rule out pigmented mimics.

Primary intracranial malignant melanoma: proposed treatment protocol and overall survival in a single-institution series of 15 cases combined with 100 cases from the literature

OBJECTIVE

The overall survival and pertinent adverse factors for primary intracranial malignant melanoma (PIMM) have not been previously determined. This aim of this study was to determine the rates of progression-free survival (PFS) and overall survival (OS) and identify the adverse factors for PIMM.

METHODS

This study included 15 cases from the authors' own series and 100 cases with detailed clinical data that were obtained from the literature from 1914 to 2018 using the Ovid Medline, EMBASE, PubMed, Cochrane, and EBSCO databases. Patient demographics, treatment (surgery, chemotherapy, and radiotherapy [RT]), PFS, and OS were reviewed. Data from prior publications were processed and used according to PRISMA guidelines.

RESULTS

Diffuse lesions were identified in 24 (20.9%) patients, who had a younger age (p < 0.001). The mean follow-up time was 16.6 months, and 76 (66.1%) deaths occurred. The 6-month, 1-year, 3-year, and 5-year OS rates of the whole cohort were 62.8%, 49.9%, 28.9%, and 17.2%, respectively, with an estimated median survival time (EMST) of 12.0 months. The multivariate analysis revealed that gross-total resection (GTR) (HR 0.299, 95% CI 0.180-0.497, p < 0.001), radiotherapy (HR 0.577, 95% CI 0.359-0.929, p = 0.024), and chemotherapy (HR 0.420, 95% CI 0.240-0.735, p = 0.002) predicted a better OS. The EMST was 5.0 months in patients with diffuse-type PIMM and 13.0 months in patients with the solitary type. Patients receiving GTR with adjuvant RT and/or chemotherapy (GTR + [RT and/or chemo]) had significantly higher 1-year and 5-year OS rates (73.0% and 40.1%, respectively) and a longer EMST (53 months) than patients who underwent GTR alone (20.5 months) or RT and/or chemotherapy without GTR (13.0 months).

CONCLUSIONS

Optimal outcomes could be achieved by radical resection plus postoperative radiotherapy and/or chemotherapy. Patients with diffuse PIMM have a more severe clinical spectrum and poorer survival than patients with solitary PIMM. Immunotherapy and targeted therapy show promise as treatment options for PIMM based on results in patients with brain metastases from extracranial melanoma.

Primary Solitary Intracranial Malignant Melanoma: A Systematic Review of Literature

INTRODUCTION

Primary solitary intracranial malignant melanoma (PIMM) is extremely rare. In 1992, an extensive review of 81 patients with PIMM was undertaken. Imaging studies, microsurgery, and adjuvant therapy have developed considerably over the last 25 years, and targeted therapy recently has been proven successful for metastatic melanoma. These factors could influence current and future clinical PIMM results.

METHODS

We undertook a literature search of PIMM patients since 1992.

RESULTS

We reviewed 49 cases of PIMM. The mean age was 45.8 years. No significant sex difference was found. Intracranial hypertension and focal neurologic deficits were commonly observed around 70% and 40%, respectively. There were no significant differences of survival period according to tumor sites. Surgeries were performed in 42 of 49 patients with PIMM reviewed (92%). The mean survival of the gross total removal group was significantly longer than that of surgical results (>22 months vs. 12 months (interquartile range: 5-22 months; P = 0.026). For adjuvant therapy, 9 patients underwent chemotherapy and 18 patients underwent radiotherapy postoperatively There was no significant difference in survival period between with and without adjuvant therapies. Leptomeningeal enhancement diagnosed in the initial MRI, was the worst prognostic factor.

CONCLUSIONS

Gross total removal of the PIMM was the most promising treatment. Currently adjuvant therapy has not been associated with the survival period. To improve clinical outcome, immunotherapy and targeted therapies are likely to become more important.