15 May 2008 – Case of the Week #119


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We thank Dr. Nazar M. T. Jawhar, University of Science and Technology Hospital, Sana’a-Yemen for contributing this case.  To contribute a Case of the Week, email NatPernick@Hotmail.com with the clinical history, your diagnosis and microscopic images in JPG, GIF or TIFF format (send as attachments, we will shrink if necessary).  Please include any other images (gross, immunostains, etc.) that may be helpful or interesting.  We will write the discussion (unless you want to), list you as the contributor, and send you $35 (US dollars) for your time after we send out the case.  Please only send cases with high quality images and a diagnosis that is somewhat unusual (or a case with unusual features).


Case of the Week #119


Clinical History


A 17 year old woman presented with ataxia, and an intraventricular mass within the lateral ventricle was identified by imaging.  A biopsy was performed.


Micro images: image #1#2#3#4#5#6#7  


What is your diagnosis?




























Central (differentiated) neurocytoma (WHO grade II)




Central neurocytoma, first described in 1982 (Acta Neuropathol 1982;56:151), is a common tumor of the septum pellucidum in young adults but still represents less than 1% of all CNS tumors.  It commonly grows into the lateral or third ventricle.  It often presents with increased intracranial pressure due to obstructive hydrocephalus, and exceptionally with sudden death due to hemorrhage (Am J Forensic Med Path 1999;20:180).  Similar tumors within CNS parenchyma are called extraventricular neurocytoma. 


Grossly, it is well demarcated from surrounding tissue, and is gray and friable  It may be gritty due to microcalcifications.  Microscopically, it has well developed neuronal features, including monotonous bland cells with modest cytoplasm, halos similar to oligodendroglioma, and salt and pepper chromatin.  Tumor cells are embedded in an eosinophilic fibrillar matrix with rare Homer Wright rosettes and ganglion cells.  Necrosis or mitotic figures occur rarely, if at all, and there is no endothelial proliferation.


The tumor cells are immunoreactive for synaptophysin, NeuN (strong, Histopathology 2006;48:438) and neuron specific enolase, but negative for GFAP, although reactive astrocytes are GFAP+.  The tumor cells also show low Ki-67 (<2%) immunostaining.


The differential diagnosis includes glioma (no/few halo cells, no/focal neuronal features, strongly GFAP+), oligodendroglioma (negative or focal for neuronal markers) and clear cell ependymoma (negative for neuronal markers, strongly positive for GFAP, vimentin and EMA).


These tumors have a good prognosis after complete surgical excision or gamma knife radiosurgery (Cancer 2007;110:2276), although up to 1/3 recur or progress (Int J Radiat Oncol Biol Phys 2007;67:1145).  Recurrence is associated with incomplete excision, or the presence of necrosis, mitotic activity / increased proliferation rates or microvascular proliferation (Cancer 2000;89:1111, Clin Neurol Neurosurg 2008;110:129).


Additional references: Louis: WHO Classification of Tumours of the Central Nervous System (4th Edition, Vol 1)





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