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In which of the following sites - doc_vic - Printable Version +- USMLE Forum - Largest USMLE Community (https://www.usmleforum.com) +-- Forum: USMLE Forum (https://www.usmleforum.com/forumdisplay.php?fid=1) +--- Forum: Step 1 (https://www.usmleforum.com/forumdisplay.php?fid=2) +--- Thread: In which of the following sites - doc_vic (/showthread.php?tid=397868) |
In which of the following sites - doc_vic - ArchivalUser - 03-31-2009 In which of the following sites do myxopapillary ependymomas most frequently occur? A. Cerebellum B. Conus medullaris C. 4th ventricle D. Lateral ventricles E. Midbrain 0 - ArchivalUser - 03-31-2009 b? 0 - ArchivalUser - 03-31-2009 CC... in children------------4 th ventrical in adult------------>spinal cord---->B conus medullaris also correct is it? 0 - ArchivalUser - 03-31-2009 cccc fourth ventricle 0 - ArchivalUser - 03-31-2009 C? 0 - ArchivalUser - 03-31-2009 BBB. conus medullaris. 0 - ArchivalUser - 03-31-2009 i will go for C 0 - ArchivalUser - 03-31-2009 cc 0 - ArchivalUser - 03-31-2009 The correct answer is B. Myxopapillary ependymoma is a variant of ependymoma, a tumor arising from ependymal cells. Histologically, myxopapillary ependymoma contains a myxoid (mucus-rich) intercellular matrix, in which spindly neoplastic ependymal cells are arranged in a fascicular and papillary pattern (hence its designation). It is a benign tumor that almost always occurs in the distal segment of the spinal cord, ie, the conus medullaris. Once excised, the patient is cured. The cerebellum (choice A) is the favorite site for pilocytic astrocytomas, medulloblastomas, and hemangioblastomas, but not ependymomas. In general, classic ependymomas occur in close proximity to the ventricular cavities, specifically, the 4th ventricle (choice C) in children and the lateral ventricles (choice D) in adults. The myxopapillary variant does not occur in either location. A midbrain location (choice E) would be truly exceptional for any type of ependymoma. |