Primary intramedullary neurocytoma: Case report and literature analysis

Background: Primary intramedullary neurocytoma is extremely rare. Due to its rarity, it is difficult to collect a wide series in a single institution to perform a survival analysis and give indications about prognosis and treatment. Case Description: Here, we report on a case of a 37-year-old woman with primary intramedullary neurocytoma and perform a systematic statistical analysis of cases reported in the literature. Of 21 articles found, 15 studies and the present case (22 patients) were eligible for the analysis. We studied the impact of age, sex, number of involved levels (≤2 vs. >2), entity of resection, postoperative radiotherapy (RT), proliferation index (Ki67) on the neurological outcome of patients, and on the recurrence of the tumor. Comparison of categorical variables was performed by the χ2 statistic. The Kaplan–Meier curves were plotted to calculate the progression-free survival (PFS) of these patients. P < 0.05 was considered as statistically significant. The 1-year PFS was 95.45% and the 2-year PFS was 86.36%. A gross total resection was associated to a worsening of the neurological function with no impact on the tumor recurrence. Adjuvant RT significantly improved the neurological function. A lower Ki67 was strongly associated with a lower tumor recurrence. Conclusions: We think that the goal of the surgery should be to preserve a good neurological function even if a residual tumor has to be left. Ki67 should be always evaluated due to its impact on the prognosis. Although adjuvant RT significantly improved the neurological function, its role in preventing the tumor recurrence is not clearly defined.