Treatment of atypical neurocytomas

Abstract

BACKGROUND The majority of central neurocytomas are benign. Approximately 25% of these rare central nervous system tumors are more aggressive, with an MIB‐1 labeling index > 2% or atypical histologic features, and are classified as atypical neurocytomas. The objective of this analysis was to define the optimal treatment for patients with these atypical tumors. METHODS The first atypical neurocytoma was described in 1989. The patients reported since then were reviewed for age, gender, extent of resection, MIB‐1 index, histology, irradiation, local control, and survival. In addition to the data available in the literature, more relevant data were obtained from the authors of that literature. Treatment approaches included complete resection alone (CR), complete resection followed by radiotherapy (CR‐RT), incomplete resection alone (IR), and incomplete resection followed by radiotherapy (IR‐RT). These four therapies were compared for local control and survival using Kaplan–Meier analysis and the log‐rank test. RESULTS Complete data were available on 85 patients (15 patients who underwent CR, 13 patients who underwent CR‐RT, 17 patients who underwent IR, and 40 patients who received IR‐RT). Local control rates at 3 years and 5 years were 73% and 57% after CR, 81% and 53% after CR‐RT, 21% and 7% after IR, and 85% and 70% after IR‐RT, respectively (P < 0.0001). Survival rates at 3 years and 5 years and were 93% and 93% after CR, 90% and 90% after CR‐RT, 65% and 43% after IR, and 87% and 78% after IR‐RT, respectively (P = 0.0076). CONCLUSIONS Patients who underwent CR achieved better local control and survival rates compared with patients who underwent IR. After IR, patients appeared to benefit from RT. A beneficial effect of RT after CR was not observed. Cancer 2004;100:814–7. © 2004 American Cancer Society.

Different Central Localizations, Different Histopathologies, Benefits, and Side Effects of Radiotherapy in Neurocytoma

“…Nevertheless, atypical histological features or centrally located atypical neurocytomas with high-grade mitotic activity are associated with high recurrence rates and unfavorable prognosis. [11,12] Whereas typical features of extraventricular neurocytomas are similar, they have obviously worse prognosis that requires adjuvant therapies. [13,14] Primary treatment of neurocytoma is total surgical excision if possible.…”

“…Central neurocytoma patient in the present series with MIB-1 labeling index of <2% who underwent STR surgery was irradiated with a dose of 60 Gy/30fr and was still alive after 60 months without any signs of recurrence. Rades et al [12] found that 3-and 5-year local control rates in patients with atypical central neurocytoma were 73% and 57% in total resection group (n=15), and 60% and 31% in STR group. In the present series, the local control rate was 75%.…”

5-Aminolevulinic Acid Fluorescence Discriminates the Histological Grade of Extraventricular Neurocytoma

“…EVNs are rare, and their clinical characteristics still need to be evaluated. The radiological findings of EVNs mimic gliomas and are effectively treated with complete resection, regardless of histological grade [6,7]. When EVNs display atypical histological features such as vascular proliferation, necrosis, increased mitotic activity and an increased proliferation index, they are classified as atypical EVNs [6,7].…”

“…The limited number of EVNs and the heterogeneous radiological findings make the diagnosis of these tumors difficult prior to surgery, and glioma is the most common radiological tentative preoperative diagnosis. The degree of resection, however, is very important for patient prognosis in both classic and atypical EVNs [6,7]. …”

Gamma Knife Radiosurgery for Central Neurocytoma: Retrospective Analysis of Fourteen Cases with a Median Follow-Up Period of Sixty-Five Months

“…One of our patients, a 30-year-old man with subtotally resected CN, presents an example of a favorable response to GKRS after a follow-up period of 36 months, though the pathological examination revealed anaplastic features and a high MIB-1 labeling index of 7%. Rades et al [34] studied 85 patients from published reports with tumors that were identified as atypical neurocytomas on the basis of an MIB-1 labeling index of 1 2%. Recently published reports showed that an elevated MIB-1 labeling index of 1 2% is predictive of tumor recurrence and an atypical appearance [35,36] .…”