title: Primary intramedullary neurocytoma: Case report and literature analysis.
abstract: 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.
  
  
  METHODS
  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 χ (2) 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.
authors.affiliation: Department of Neurosurgery, Institute of Neurosurgery, Catholic University, Rome, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Montano
authors.affiliation: Department of Neurosurgery, Institute of Neurosurgery, Catholic University, Rome, Italy.
authors.forename: Rina
authors.initials: R
authors.lastname: Di Bonaventura
authors.affiliation: Department of Pathology, Institute of Pathology, Catholic University, Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Coli
authors.affiliation: Department of Neurosurgery, Institute of Neurosurgery, Catholic University, Rome, Italy.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Fernandez
authors.affiliation: Department of Neurosurgery, Institute of Neurosurgery, University of Verona, Verona, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Meglio
keywords: Adjuvant radiotherapy; Ki67; intramedullary neurocytoma; progression-free survival; surgery