Central neurocytoma is a well-differentiated neuronal tumor (WHO Grade II) located in the lateral ventricle body near the foramen of Monro, seen in young adults (20-40 years). The typical imaging appearance is a 'Swiss cheese' or 'bubbly' pattern — a heterogeneous mass with coexisting cystic and solid components. Its intraventricular location, young age group, and characteristic appearance distinguish it from other ventricular tumors. Prognosis is generally favorable; cure rate with total resection is high. Immunohistochemically, it is synaptophysin-positive, confirming neuronal differentiation.
Age Range
20-40
Peak Age
30
Gender
Equal
Prevalence
Rare
Central neurocytoma arises from subependymal progenitor cells or neurons of the septum pellucidum and grows intraluminally in the lateral ventricle body (usually near the foramen of Monro). Tumor cells show small, round, uniform neurocyte morphology and express neuronal markers such as synaptophysin and NeuN — confirming neuronal differentiation. The cystic-solid ('bubbly') appearance of the tumor microscopically originates from neurocyte clusters surrounded by neuropil islands and intervening areas of cystic degeneration. On MRI, cystic areas appear T2 hyperintense while solid component shows intermediate signal intensity; this complex internal structure creates the 'Swiss cheese' appearance. The tumor's rich vascular structure (thin-walled capillaries) leads to flow void structures on MRI and moderate heterogeneous enhancement on contrast sequences. Calcification is seen in 50-70% of cases and reflects the slow growth rate of the tumor. Because it attaches to the septum pellucidum or ependyma, it can typically obstruct the foramen of Monro with a broad base and cause obstructive hydrocephalus. MKI (mitotic index) is low and associated with favorable prognosis; however, 'atypical' neurocytomas with MKI >2% may have a more aggressive course.
A heterogeneous 'bubbly' mass in the lateral ventricle body (near the foramen of Monro) consisting of multiple small cystic areas and intervening solid components on T2, with broad-based attachment to the septum pellucidum in a young adult is the signature finding of central neurocytoma. This appearance is not this typical in any other ventricular tumor.
On T2-weighted sequences, a heterogeneous mass with 'bubbly' or 'Swiss cheese' appearance is seen in the lateral ventricle body. Multiple small cystic areas appear T2 hyperintense while solid components show intermediate signal intensity (near brain parenchyma or mildly hyperintense). This complex internal structure reflects cystic degeneration areas between neurocyte clusters. Broad-based attachment to the septum pellucidum or ependyma is observed. Flow void structures indicate vascular richness.
Report Sentence
On T2-weighted sequences, a heterogeneous 'bubbly' mass measuring [size] cm containing multiple cystic areas and solid components is observed in the [right/left] lateral ventricle body, showing broad-based attachment to the septum pellucidum.
On T1-weighted sequences, the solid component appears isointense or mildly hypointense relative to brain parenchyma. Cystic areas appear T1 hypointense (near CSF). On contrast-enhanced T1 sequences, the solid component shows moderate heterogeneous enhancement — due to tumor vascular structure. Cystic areas show no enhancement. In rare cases, if hemorrhage is present within cysts, T1 hyperintense foci may be seen but this is not a classic finding.
Report Sentence
On T1-weighted sequences, the lesion contains [isointense/mildly hypointense] solid component and hypointense cystic areas. Moderate heterogeneous enhancement is observed in the solid component on contrast-enhanced sequences.
On non-contrast CT, an isodense or slightly hyperdense heterogeneous mass is seen in the lateral ventricle body. Calcification is observed in 50-70% of cases and reflects the slow growth rate — punctate, nodular, or coarse calcification pattern may be present. Cystic areas appear hypodense. Moderate heterogeneous enhancement is seen on contrast CT. Obstructive hydrocephalus may accompany. CT is superior to MRI for calcification detection.
Report Sentence
On non-contrast CT, a heterogeneous mass measuring [size] cm [with calcification/without calcification] is observed in the [right/left] lateral ventricle body. [Obstructive hydrocephalus is present/absent].
On DWI sequences, mild to moderate diffusion restriction may be observed in the solid component — reflecting moderate cellularity of the tumor. ADC values are mildly lower than normal brain parenchyma but not as pronounced as high-grade gliomas or lymphoma. Cystic areas show free diffusion (high ADC). DWI/ADC evaluation may help estimate tumor aggressiveness and distinguish atypical neurocytoma from classic (atypical: more pronounced restriction).
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On DWI sequences, mild to moderate diffusion restriction is observed in the solid component, with ADC value calculated as [value] x 10-3 mm2/s. Free diffusion is present in cystic areas.
On FLAIR sequences, the mass has heterogeneous appearance: solid components are hyperintense (near brain parenchyma or mildly hyperintense), cystic areas show variable signal — protein-containing cysts are hyperintense (different from CSF, non-suppressed), pure CSF-like cystic areas are suppressed. This heterogeneous FLAIR appearance reflects the complex internal structure of the tumor and distinguishes from homogeneous lesions such as colloid cyst or arachnoid cyst. If periventricular edema is present, additional hyperintense signal may be seen on FLAIR.
Report Sentence
On FLAIR sequences, the mass has heterogeneous appearance with hyperintense solid components and variable signal in cystic areas.
On perfusion MRI (DSC), moderately increased cerebral blood volume (CBV) is observed in the solid component — reflecting the tumor's rich vascular structure. CBV values are higher than normal white matter but lower than glioblastoma or meningioma. rCBV (relative CBV) ratio is typically between 2-4. This perfusion characteristic reflects the tumor's biological behavior: well-differentiated, slow-growing but with vascular richness. In atypical neurocytomas, rCBV may be higher. No perfusion increase is observed in cystic areas.
Report Sentence
On perfusion MRI, moderately increased CBV is observed in the solid component, with rCBV ratio calculated as [ratio]. No perfusion increase is detected in cystic areas.
On MR spectroscopy (MRS), a glycine peak (3.55 ppm) may be observed in central neurocytoma — a nearly specific finding for neuronal tumors and valuable for distinguishing from other intraventricular tumors (ependymoma, subependymoma, choroid plexus papilloma). Choline/creatine ratio is mildly to moderately elevated (cellular turnover), NAA peak is variable (despite neuronal differentiation, tumoral tissue differs from normal neurons). Alanine peak may also be seen. This metabolic profile is a powerful additional diagnostic tool for distinguishing central neurocytoma from other ventricular tumors.
Report Sentence
On MR spectroscopy, a glycine peak (3.55 ppm) and mildly elevated choline/creatine ratio are observed in the solid component, suggesting a tumor with neuronal differentiation.
Criteria
In the lateral ventricle body, young adult (20-40 years), low mitotic index (MKI <2%), synaptophysin positive, NeuN positive. Bubbly appearance, moderate enhancement. Good prognosis — 5-year recurrence-free survival >90% with gross total resection.
Distinct Features
Bubbly/Swiss cheese appearance is prominent. Calcification common. Mild-moderate diffusion restriction. rCBV 2-4. Glycine peak on MRS. Broad-based attachment to septum pellucidum. Low recurrence rate after surgery.
Criteria
Increased mitotic index (MKI >2-3%), vascular proliferation, necrosis areas. More aggressive biological behavior, higher recurrence rate. More heterogeneous on imaging, more pronounced enhancement, more pronounced diffusion restriction. Higher rCBV (>4). Adjuvant radiotherapy may be needed.
Distinct Features
Larger, more heterogeneous, more pronounced enhancement compared to classic neurocytoma. Necrosis areas and peritumoral edema more prominent. More pronounced diffusion restriction on DWI (lower ADC). Addition of radiotherapy after surgery recommended. 5-year survival 70-80%.
Criteria
Rare variant — located within brain parenchyma (intra-axial), no direct relationship with ventricle. Histologically identical to central neurocytoma (synaptophysin positive). Frontal or temporal lobe most common. On imaging, intra-axial heterogeneous mass, cystic-solid components, variable enhancement. Prognosis similar to central neurocytoma but surgery may be more challenging.
Distinct Features
Location not related to ventricle — intra-axial heterogeneous mass. Preoperative diagnosis difficult (may be confused with glioma). Synaptophysin immunohistochemistry is essential for diagnosis. Bubbly appearance may be less prominent. Glycine peak on MRS aids diagnosis.
Distinguishing Feature
Oligodendroglioma is typically a cortical/subcortical intra-axial tumor (not intraventricular). Calcification is common (70-90%) but location is different (frontal lobe most common). T2 hyperintense with cortical involvement. IDH mutation and 1p/19q co-deletion as molecular markers are absent in neurocytoma. Glycine peak on MRS seen in neurocytoma is not present in oligodendroglioma.
Distinguishing Feature
Ependymoma can be an intraventricular mass but prefers the fourth ventricle in children and lateral/third ventricle in adults. 'Toothpaste sign' (plastic extension through foramina) is characteristic. More heterogeneous enhancement, cystic/necrotic areas, calcification. Age distribution differs (children and young adults). Glycine peak is not seen on MRS. May show lower rCBV than neurocytoma on perfusion. EMA (Epithelial Membrane Antigen) positive, synaptophysin negative — opposite of neurocytoma.
Distinguishing Feature
Colloid cyst is a small (usually <20mm), homogeneous, T1 hyperintense, non-enhancing round lesion in the anterior third ventricle (foramen of Monro). Unlike neurocytoma, it does not show solid component or complex cystic-solid internal structure, does not enhance, has no CBV increase on perfusion, and does not contain calcification. Homogeneous signal and absence of enhancement is the differentiating feature. Typically found incidentally or with hydrocephalus.
Distinguishing Feature
Choroid plexus papilloma is an intensely enhancing lobulated intraventricular mass. In children lateral ventricle trigone, in adults third/fourth ventricle is preferred. Unlike neurocytoma, it enhances very avidly and homogeneously (hypervascular), shows markedly high rCBV on perfusion (>5-6). Does not typically show bubbly appearance, has more lobulated and papillary structure. May cause hydrocephalus due to CSF overproduction (communicating). Glycine peak is not seen on MRS.
Urgency
moderateManagement
Cerrahi rezeksiyon (mikrocerrahi transkortial/transkallosal veya endoskopik) birincil tedavi. Gross total rezeksiyon ile kur orani yuksek (%90+). Subtotal rezeksiyon durumunda adjuvan radyoterapi (stereotaktik radyocerrahi veya fraksiyonlu) tartismali ancak atipik norositomda onerili. Kemoterapi rolu sinirli.Biopsy
NeededFollow-up
Cerrahi sonrasi 3 ay kontrol MR, sonra yillik takip (en az 5-10 yil). Atipik norositomda daha sik takip (6 aylik). Nuks izlenmesi icin kontrastli MR esansiyeldir.Central neurocytoma is a well-differentiated neuronal tumor seen in young adults in the lateral ventricle body. Imaging appearance is characteristic ('bubbly' / 'Swiss cheese') and preoperative diagnosis is usually accurate by experienced neuroradiologists. Prognosis with gross total resection is excellent (>90% 5-year survival). Atypical neurocytomas (MKI >2%, necrosis, vascular proliferation) may have a more aggressive course and require adjuvant therapy. Perfusion MRI (rCBV) and MRS (glycine peak) provide additional diagnostic value in preoperative evaluation. Emergency ventricular drainage may be needed if hydrocephalus is present. Definitive diagnosis is established with histological + immunohistochemical (synaptophysin, NeuN) confirmation.
Central neurocytoma is usually a WHO Grade 2 benign tumor with excellent prognosis after surgical resection. Recurrence rate is low after total resection. Adjuvant radiotherapy may be considered after subtotal resection. Atypical neurocytomas (high MIB-1 index) have a more aggressive course.