Diffusion weighted MR imaging and proton MR spectroscopy findings of central neurocytoma with pathological correlation.
OBJECTIVE
Three cases of histopathologically confirmed central neurocytoma (CN) are presented, emphasizing diagnostic imaging issues: conventional magnetic resonance imaging with Proton magnetic resonance spectroscopy (MRS) and diffusion-weighted imaging (DWI) findings of CN.


METHODS
Patients age ranged from 17 to 32 years, Imaging include a CT scan and MR examination with DWI and proton MRS on a 1.5-T system. DWI and subsequent apparent diffusion coefficient (ADC) were obtained in all. Single voxel MRS was performed prior to surgery using a point resolved spectroscopy sequence (PRESS) with short 35 ms and long echotime (TE) 144 ms, associated with a two-dimensional chemical Shift Imaging (2D-CSI) with 144 ms TE (one case). Histopathological examination included immunostaining with synaptophysin.


RESULTS
With the long TE, a variable amount of glycine with markedly increased choline, very small to almost complete loss of N-acetylaspartate and creatine, and inverted triplet of alanine-lactate were observed in all three patients. Increased glutamate and glutamine complex (Glx) was also observed in all with short TE. DWI demonstrated variable low ADC which appeared well correlated with the tumor signal intensity and cell density: the most homogeneous and highly dense cellular tumor with increased nucleus to cytoplasm ratio demonstrated the lower ADC. Histological pattern was typical in two cases and demonstrated an oligodendroglioma-like pattern in one case. Positivity for synaptophysin confirmed the neuronal origin in all.


CONCLUSIONS
The demonstration within an intraventricular tumor of both glycine and alanine on MRS along with high choline, bulky Glx and restricted diffusion appear diagnostic of CN.
Service de radiologie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia. Electronic address: kalthoum.tlili@rns.tn.
Kalthoum
K
Tlili-Graiess
Service de radiologie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia.
Nadia
N
Mama
Service de radiologie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia.
Nadia
N
Arifa
Service de radiologie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia.
Khaled
K
Kadri
Service de radiologie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia.
Ibtissem
I
Hasni
Service de neurochirurgie, hôpital Sahloul, route ceinture, 4011 Sousse, Tunisia.
Hedi
H
Krifa
Laboratoire d'anatomopathologie, hôpital Farhat Hached, rue Ibn Jazzar, 4031 Sousse Ezzouhour, Sousse, Tunisia.
Moncef
M
Mokni
D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D001932:Brain Neoplasms / Q000737:chemistry* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D018306:Neurocytoma / Q000737:chemistry* / Q000473:pathology*; D018377:Neurotransmitter Agents / Q000032:analysis*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D015415:Biomarkers; D018377:Neurotransmitter Agents
Central neurocytoma; Diffusion Weighted Imaging; MR spectroscopy; MRI