Department of Pathology, University of Oklahoma Health Sciences Center

NeuroTest Question #72 Next question Previous question

Answer: Paraganglioma (E)  Level of difficulty: 3 NeuroTest NeuroLearn NeuroHelp

Discussion: 

• Pathology of the case: The characteristic organoid or “Zellballen” nest of cells is characteristic for a diagnosis of paraganglioglioma. These tumors can be seen in the filum terminale and other nerve roots. They are also common in the head and neck area.
• Meningioma: Meningioma can occur in this location. They may invade into the dura and surrounding dense fibrous tissue and give rise to tumor nest. However, they do not form the characterstic organoid or “Zellballen” nest of cells as illustrated in this case. [Click here to see a picture of schwannoma]
• Schwannoma: Schwannoma can occur in this location but do not display this type of  organoid or “Zellballen” nest of cells. [Click here to see a picture of schwannoma]
• Disseminated medulloblastoma: The neuroendocrine features of the nuclei can go along with medulloblastoma. However, there is too much cytoplasm for medulloblastoma. Besides, disseminated medulloblastoma do not form the organoid or “Zellballen” nest of cells architecture. [Click here to see a picture of medulloblastoma]
• Myxopapillary ependymoma: Myxopapillary ependymoma typically arises in the filum terminale. Other thant that, there is very few morphologic similarities between these two entities. [Click here to see a picture of myxopapillary ependymoma]
• Paraganglioma of the filum terminale: These tumors are more common in male and present most often in between the 4^th to 6^th decades. Most of them have the classic Zellballen architecture that is illustrated here. Gangliocytic paraganglioma contains mature ganglion cells and cells that have transitional histology between chief cells and ganglion cells. Gangliocytic paraganglioma are also found in the duodenum and other regions. Other uncommon pattern include tumors  that have morphologic features suggestive of ependymoma and also tumor cells arranging in cords and surrounded by fibrous tissue. Immunohistochemistry, paraganglioma cells are positive for chromogranin and synaptophysin. The sustentacular cells in periphery of the nest are positive for S100 and glial fibrillary acidic protein (GFAP). Cytokeratin are often demonstrated in paragangliomas of the cauda equina and filum terminale. At ultrastructural level, they have dense core (neurosecretory) granules. [Click here to see a case]

Comment: KarMing-Fung@ouhsc.edu