Clinical Course of Central Neurocytoma with Malignant Transformation—An Indication for Craniospinal Irradiation

Abstract

Central neurocytoma is generally considered to be a benign tumor and the literature suggests that a cure may be attained by surgery ± adjuvant focal irradiation. However, there is a need for change in the therapeutic strategy for the subgroup of patients with aggressive central neurocytoma. An example case is presented and the literature on central neurocytoma cases with malignant features and dissemination via the cerebrospinal fluid is reviewed and the radiotherapeutic strategies available for central neurocytoma treatment is discussed. Nineteen cases including the present report with a malignant course and cerebrospinal fluid dissemination have been described to date, most of them involving an elevated MIB-1 labeling index. Our case exhibited atypical central neurocytoma with an initially elevated MIB-1 labeling index (25-30 %). The primary treatment included surgery and focal radiotherapy. Three years later the disease had disseminated throughout the craniospinal axis. A good tumor response and symptom relief were achieved with repeated radiation and temozolomide chemotherapy. Central neurocytoma with an initially high proliferation activity has a high tendency to spread via the cerebrospinal fluid. The chemo- and radiosensitivity of the tumor suggest a more aggressive adjuvant therapy approach. Cases with a potential for malignant transformation should be identified and treated appropriately, including irradiation of the entire neuroaxis and adjuvant chemotherapy may be considered.

Malignant progression of an extraventricular neurocytoma arising from the VIIIth cranial nerve: A case report and literature review

“…Taking into account the previous literature, malignant transformation of CN has been reported . Interestingly, Amagasa et al .…”

“…In reality, the tumor had obviously occurred at the portion of the VIIIth cranial nerve based on the first operation findings of the present case, which supported the suggestion of Onguru et al 14 Taking into account the previous literature, malignant transformation of CN has been reported. [16][17][18][19] Interestingly, Amagasa et al reported that malignant transformation might occur in CNs that show very low initial Ki-67 labeling indices. 17 Tanaka et al reported a case of recurrent CN that was diagnosed 10 years after surgical resection and consecutive stereotactic radiotherapy.…”

Systematic Analysis of Clinical Outcomes Following Stereotactic Radiosurgery for Central Neurocytoma

“…MIB-1 (Ki-67) labeling index has been demonstrated to be the most important marker of potentially malignant behavior in CN [4565758596061626364]. CN is considered atypical if the MIB-1 (Ki-67) labeling index is greater than or equal to 2% [45758].…”

Central Neurocytoma: A Review of Clinical Management and Histopathologic Features

“…Söylemezoglu et al [52] found that a MIB-1 LI >2% correlated with microvascular proliferation and suggested that a CN with MIB-1 LI >2% should be termed ‘atypical’ [4]. Atypical CN are also known to spread through the cerebrospinal fluid and metastasize in the ventricles or the spinal cord [100101102103]. …”