Central neurocytoma: a clinical, radiological and pathological study of nine cases

Abstract

Purpose: Central neurocytoma is a rare intraventricular brain tumor that affects young adults and presents with increased intracranial pressure secondary to obstructive hydrocephalus. Typically, it has a favorable prognosis after adequate surgical intervention, but in some cases the clinical course is more aggressive. In this report, we describe the diagnosis and treatment of central neurocytoma in a series of patients at our institution.

Patients and methods: Our series of nine patients (M:F=2:7, mean age, 28.2 years) with ventricular tumors showed typical radiological, histologic and immunohistochemical features of central neurocytoma. Most patients received craniotomy with removal of the tumor through transcallosal or transcortical approach. The surgical and histopathologic data of these patients were reviewed and analyzed.

Results: The prognosis is generally favorable. Although most patients were alive and well at the last follow-up, two developed recurrence. Typical histologic features of recurrent neurocytoma include high proliferative activity (MIB-1 labeling index: 2.0-6.8%), prominent vascular proliferation and remarkable synaptophysin expression. Two patients (non-recurrent) died during follow-up due to sepsis or central failure. The MIB-1 labeling indices were as high as 2.2-5.4% for these two patients.

Conclusion: Although central neurocytoma is generally a benign neoplasm, some variant forms of recurrence are also present. Complete resection provides favorable long-term prognosis in most cases. Recurrent tumors are often local and the patients seem to recover well after a second resection followed by radiotherapy. Histologic features such as tumor proliferation (MIB-1 labeling index), vascular proliferation, and synaptophysin expression are often prominent in the recurrent tumor. We recommend that these histologic features be considered for tumor recurrence during treatment and follow-up of these patients.

Fig. 1

Preoperative axial T1-weighted magnetic resonance (MR) images of a patient with central neurocytoma. A. Before contrast enhancement; B. After contrast enhancement, a large mildly enhanced mass with “soap-bubble” appearance was shown in the left lateral ventricle and attaching to the septum pellucidum. Contrast-enhanced T1-weighted magnetic resonance images 28 months after the first resection demonstrated a recurrent central neurocytoma in Patient 7 as shown in Table 1. C. axial view; D. coronal view. Postoperative contrast-enhanced T1-weighted magnetic resonance images 43 months after total removal of the recurrent tumor and fractionated radiotherapy showed no enhanced mass in the left lateral ventricle. E. axial view; F. coronal view.

Fig. 2

Fig. 2A. Photomicrograph (hematoxylin and eosin stain, 200x) of central neurocytoma. Numerous round nuclei with delicate chromatin and indistinct cell border can be seen in the fibrillary and well-vascularized matrix. Some cells have a perinuclear halo. Mild nuclear pleomorphism and mitosis scattered throughout the section. 2B. Photomicrograph (100x) showing strong immunoreactivity of synaptophysin in central neurocytoma. Synaptophysin in the tumor presented in a diffuse fibrillar pattern. 2C. Photomicrograph (200x) revealing immunoreactivity of Ki-67 in the first-resected central neurocytoma of patient 7. The proliferation index (MIB1-LI) is evaluated as 6.8%.