WBR0613

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category
Sub Category
Prompt	[[Prompt::A 10-year-old child was brought by his mother to the neurology clinic for worsening chronic headache and gait disturbance. A well-circumscribed mass with solid and cystic component is detected in the cerebellar region on CT-scan. Shown below is a pathology image of the tumor following resection. The tumor is most likely derived from cells that have which of the following functions? ]]
Answer A	AnswerA::Reactive gliosis
Answer A Explanation	AnswerAExp::
Answer B	AnswerB::Phagocytosis
Answer B Explanation	AnswerBExp::
Answer C	AnswerC::Myelin production
Answer C Explanation	AnswerCExp::
Answer D	AnswerD::Action potential generation
Answer D Explanation	AnswerDExp::
Answer E	AnswerE::Production of CSF
Answer E Explanation	AnswerEExp::
Right Answer	RightAnswer::A
Explanation	[[Explanation::The age of the patient, the location of the mass in the cerebellar lesion and the cystic and solid characteristic of tumor increase the suspicion of an astrocytoma. The pathology image of the tumor reveals Rosenthal fibers which are eosinophilic corkscrew fibers that are found in pilocytic astrocytoma. The diagnosis can be confirmed with GFAP staining. Astrocytes play a role in the maintenance of the blood brain barrier, regulation of potassium metabolism and reactive gliosis. Shown below is an image depicting Rosenthal fibers. Educational objective: Pilocytic astrocytoma is a tumor arising from astrocytes and usually affects children. It is commonly located in the posterior fossa, but can be found in the supratentorial area. It is pathologically characterized by the presence of Rosenthal fibers which are eosinophilic corkscrew fibers. Educational Objective: References: ]]
Approved	Approved::No
Keyword
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::