|Year : 2020 | Volume
| Issue : 2 | Page : 159-162
Rare case of central neurocytoma in a middle-aged Nigerian woman presenting with chronic headache and visual impairment
Austine Abebe Osawe1, Ayinde Babatunde Junaid1, Abubakar Otaru Aliyu2, Mohammed Kabir Saleh3
1 Department of Radiology, Nigeria Navy Reference Hospital, Ojo, Lagos, India
2 Department of Otorhinolaryngology, Nigeria Navy Reference Hospital, Ojo, Lagos, India
3 Department of Radiology, Aminu Kano Teaching Hospital, Bayero University, Kano, Nigeria
|Date of Submission||27-Nov-2019|
|Date of Acceptance||30-Jun-2020|
|Date of Web Publication||24-Sep-2020|
Dr. Austine Abebe Osawe
Department of Radiology, Nigeria Navy Reference Hospital, Ojo, Lagos
Central neurocytomas (CNs) are rare benign neuroepithelial neoplasms occurring in young- and middle-aged adults. They most commonly arise within the body of the lateral ventricle, adjacent to the septum pellucidum and foramen of Monro. Patients may be asymptomatic or may present with headache and signs of raised intracranial pressure due to hydrocephalus. Preoperative diagnosis of CN by neuroimaging, electron microscopy, and immunohistochemical methods helps in planning therapy. This case describes CN in a 42-year-old female with signs and symptoms of raised intracranial pressure, neuroimaging (magnetic resonance imaging) findings, and the management.
Keywords: Central neurocytoma, intraventricular tumor, neuroimaging
|How to cite this article:|
Osawe AA, Junaid AB, Aliyu AO, Saleh MK. Rare case of central neurocytoma in a middle-aged Nigerian woman presenting with chronic headache and visual impairment. West Afr J Radiol 2020;27:159-62
|How to cite this URL:|
Osawe AA, Junaid AB, Aliyu AO, Saleh MK. Rare case of central neurocytoma in a middle-aged Nigerian woman presenting with chronic headache and visual impairment. West Afr J Radiol [serial online] 2020 [cited 2020 Oct 20];27:159-62. Available from: https://www.wajradiology.org/text.asp?2020/27/2/159/295947
| Introduction|| |
Central neurocytomas (CNs) are low-grade tumors usually located in the lateral ventricles next to the foramen of Monroe, commonly arising from the ventricular walls or septum pellucidum.
According to the World Health Organization classification (2007), they are Grade II tumors with unclear cell of origin. Histologically, the neurocytes can resemble oligodendrocytes, hence these tumors were initially mistaken for intraventricular oligodendrogliomas.
CNs are rare tumors occurring in young adults, comprising about 0.25%–0.5% of all intracranial tumors. Seventy percent of the patients present in the third and fourth decades of life. Tumor incidence shows no significant gender preponderance.
Tumor occurrence is said to be higher among people of Asian descent, and this has been attributed to the genetic predisposition of people of this race.
Because of the rarity of this tumor, only a limited number of studies and case reports have been published.
On literature search, it was difficult to get the documented incidence of CN in the West Africa subregion.
| Case Report|| |
A 42-year-old female presented to our facility with a history of long-standing headache which was temporarily relieved by the use of analgesics. Symptom was described as dull ache that was recurrent and generalized, lasting for about 7 months before the presentation. She also described a feeling of heaviness in her head with visual impairment (double vision).
Physical examination of the patient was unremarkable, and vital signs were stable.
Neurologic evaluation revealed no deficit of sensibility. However, she had diplopia which was confirmed on ophthalmologic evaluation. Laboratory investigations which included blood chemistry and full blood count were normal. Brain magnetic resonance imaging (MRI) done revealed a well-defined, expansile, bubbly, T1 isointense and T2-mixed intensity mass abutting the septum pellucidum and occupying the lateral ventricles. It measured about 3.6 cm × 3.8 cm × 5.2 cm in size and demonstrated heterogenous enhancement following intravenous gadolinium administration. These features were typical of CN. There was associated lateral ventricular dilatation due to obstruction at the foramen of Monroe. The cerebral and cerebella hemispheres were within the normal limits.
The ocular globes, optic nerves, and extraocular muscles were preserved.
The patient was evaluated by a neurosurgeon, and a biopsy of the lesion was indicated.
The patient had total surgical excision of the lesion, and the histology report confirmed the imaging diagnosis of neurocytoma. The patient had unremarkable postsurgical outcome.
| Discussion|| |
CN was first described in 1982 by Hassoun et al. They described the tumor as comprising relatively mature neuronal population of tumor cells with benign behavior on electron microscopy.
Since its first description by Hassoun et al. till 2015, only <1000 cases of CNs had been reported worldwide.
CN generally describes neurocytomas occurring in the ventricular system. However, there are reports of atypical variants such as those occurring in extraventricular locations and malignant variety. They can be situated in the cerebral hemispheres, pons, cerebellum, spinal cord, and retina.
Half of the cases of CNs involve the lateral ventricles near the foramen of Monro, whereas 15% are located in both the lateral and third ventricles. About 13% of CNs are bilateral, and only 3% occur in the third ventricle as an isolated location. There is a single case report of a CN that arose in the fourth ventricle.
Patients usually present with features of raised intracranial pressure due to tumor location in the third and fourth ventricles causing obstruction to normal cerebrospinal fluid (CSF) flow.
Headaches are the dominant symptom and are initially nonspecific and diffuse in nature. Over time, headaches increase in frequency and intensity. Many patients are either awakened by or upon awakening from sleep with headache. Subsequently, new symptoms are added with nausea and vomiting being the next most frequent.
Patients may also present with visual impairment (visual obscuration) due to papilledema or abducens nerve palsy (manifesting as diplopia).
In addition, patients may complain of lightheadedness, impaired mentation, gait instability, and in rare cases, signs of intraventricular hemorrhage.
Our patient presented with history of chronic headache, feeling of heaviness in the head, and visual impairment (diplopia).
Computed tomography (CT) and MRI are crucial in establishing the diagnosis due to the characteristic imaging features of this tumor.
On MRI, CN appears as a well-circumscribed, heterogeneous mass with lobulated margin. The tumor is usually isointense or slightly hypointense to gray matter on T1-weighted images and hyperintense on T2-weighted images. It demonstrates mild-to-moderate enhancement with intravenous gadolinium administration and shows punctate or coarse calcifications with multiple small cysts often seen within it. These features as described were demonstrated on MR images of our patient [Figure 1] and [Figure 2].
|Figure 1: Sagittal noncontrast-enhanced T1-weighted image of the brain showing a broad-based, lobulated intraventricular mass, isointense to brain parenchyma with hypointense cystic and signal void calcific components. The mass is abutting the septum pellucidum superiorly with associated hydrocephalus due to obstruction at the foramen of Munroe|
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|Figure 2: Axial T2-weighted magnetic resonance image showing a mixed intensity intraventricular mass occupying the lateral ventricles. The horns of the lateral ventricles are grossly dilated due to obstruction at the foramen of Monroe|
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Usually, there is associated lateral ventricular dilatation due to obstruction to CSF flow at the foramen of Munroe. This was also shown in the MR images of our patient.
Prominent flow voids and intratumoral hemorrhages may be seen in some cases, but these were absent in the index case.
Magnetic resonance spectroscopy has proved a valuable tool for presurgical diagnosis of Central neurocytomas. Studies have reported these tumors to consistently show the pattern of increased choline and decreased N-acetyl aspartate levels. Typical appearance with metabolite peak at 3.55 ppm due to increased Glycine is a rather specific marker and strong feature of CNC on long TE spectra.
On CT, the tumors are iso- to slightly hyperdense with smooth margins and small low-density areas. Calcification is present in approximately 50% of all CNs. The tumors are often attached to the septum pellucidum, and usually, there is evidence of obstructive hydrocephalus.
Postcontrast CT images show relatively homogenous contrast enhancement of the tumor.
Cerebral angiography in the majority of cases demonstrates homogenous vascular staining with either a choroidal (anterior or posterior) or lenticulostriate feeding artery. Generally, no draining vein is visible.
CT and MRI can also help differentiate this tumor from similarly appearing central nervous system (CNS) masses such as intraventricular oligodendroglioma, astrocytoma, and ependymoma.
Intraventricular oligodendromas occur within the body of the lateral ventricle and have large and irregular calcifications, whereas astrocytomas and ependymomas usually lack cystic and calcific components.
Electron microscopy and immunohistochemistry help confirm the diagnosis and differentiate CN from other tumors of the CNS, such as ependymomas, astrocytomas, or oligodendromas. The tumor cells grow in sheets and clusters but rarely rosettes. The fibrillary areas can be seen to form acellular aggregates. The nuclei are round to oval with finely speckled chromatin and occasional prominent nucleoli. The cytoplasm is scanty and can be acidophilic or rarely clear. Calcification, which is seen throughout the tumor, and delicate-branching capillaries bring resemblance to oligodendroglioma, as shown in [Figure 3].
|Figure 3: (a) H and E stained light microscopy image of specimen showing typical round cells with vesicular chromatin and delicate capillary-sized vessels. (b) Slide shows positive synaptophysin staining|
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The first line of treatment is total surgical resection. Radiation therapy is indicated when complete resection is not obtained or in cases of disease recurrence or progression. The use of chemotherapy is not well established and is only usually indicated with failure of surgical or radiation treatment.
Our patient had total surgical resection of the tumor and has remained stable on follow-up.
CNs have good prognosis with excellent long-term survival (5-year survival 81%).
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3]