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.