WBR0138: Difference between revisions
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|MainCategory=Embryology | |MainCategory=Embryology | ||
|SubCategory=Neurology | |SubCategory=Neurology | ||
|MainCategory=Embryology | |||
|MainCategory=Embryology | |MainCategory=Embryology | ||
|MainCategory=Embryology | |MainCategory=Embryology | ||
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|MainCategory=Embryology | |MainCategory=Embryology | ||
|SubCategory=Neurology | |SubCategory=Neurology | ||
|Prompt=A 23-year-old male is referred to a neurologist for evaluation of a progressively worsening vertigo and hearing loss that started almost 4 months ago. A brain MRI showed bilateral cerebello-pontine angle masses. Which of the following most likely | |Prompt=A 23-year-old male is referred to a neurologist for evaluation of a progressively worsening vertigo and hearing loss that started almost 4 months ago. A brain MRI showed bilateral cerebello-pontine angle masses. Which of the following is the most likely embryological origin of the cells from which this patient’s masses arose? | ||
|Explanation=The patient presents with bilateral masses, compressing [[CN VIII]], which results in hearing loss and [[vertigo]]. The bilateral nature of the masses, the age of the patient, and the involvement of the [[CN VIII]] are all characteristic of [[neurofibromatosis type II]]. Hence, the masses are more likely bilateral vestibular [[shwannoma]]. The embryological origin of shwannomas is the [[neural crest]]. | |Explanation=The patient presents with bilateral masses, compressing [[CN VIII]], which results in hearing loss and [[vertigo]]. The bilateral nature of the masses, the age of the patient, and the involvement of the [[CN VIII]] are all characteristic of [[neurofibromatosis type II]]. Hence, the masses are more likely bilateral vestibular [[shwannoma]]. The embryological origin of shwannomas is the [[neural crest]]. | ||
|AnswerA=Mesoderm | |AnswerA=Mesoderm | ||
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* Ciliary body of the eye | * Ciliary body of the eye | ||
* Adrenal medulla | * Adrenal medulla | ||
|EducationalObjectives= The neural crest is the embryological origin of shwannomas. | |EducationalObjectives=The neural crest is the embryological origin of shwannomas. | ||
|References=First Aid 2014 page 444 | |||
|RightAnswer=E | |RightAnswer=E | ||
|WBRKeyword=Embryology, Neural crest, Schwannoma, Brain tumor, Cancer, Neurofibromatosis | |WBRKeyword=Embryology, Neural crest, Schwannoma, Brain tumor, Cancer, Neurofibromatosis | ||
|Approved=Yes | |Approved=Yes | ||
}} | }} |
Revision as of 13:03, 12 July 2014
Author | [[PageAuthor::Rim Halaby, M.D. [1] (Reviewed by Alison Leibowitz)]] |
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Exam Type | ExamType::USMLE Step 1 |
Main Category | MainCategory::Embryology |
Sub Category | SubCategory::Neurology |
Prompt | [[Prompt::A 23-year-old male is referred to a neurologist for evaluation of a progressively worsening vertigo and hearing loss that started almost 4 months ago. A brain MRI showed bilateral cerebello-pontine angle masses. Which of the following is the most likely embryological origin of the cells from which this patient’s masses arose?]] |
Answer A | AnswerA::Mesoderm |
Answer A Explanation | [[AnswerAExp::The mesoderm gives rise to:
|
Answer B | AnswerB::Endoderm |
Answer B Explanation | [[AnswerBExp::The endoderm gives rise to:
|
Answer C | AnswerC::Surface ectoderm |
Answer C Explanation | [[AnswerCExp::The surface ectoderm gives rise to:
|
Answer D | AnswerD::Neuroectoderm |
Answer D Explanation | [[AnswerDExp::The neuroectoderm gives rise to:
|
Answer E | AnswerE::Neural crest |
Answer E Explanation | [[AnswerEExp::The neural crest gives rise to:
|
Right Answer | RightAnswer::E |
Explanation | [[Explanation::The patient presents with bilateral masses, compressing CN VIII, which results in hearing loss and vertigo. The bilateral nature of the masses, the age of the patient, and the involvement of the CN VIII are all characteristic of neurofibromatosis type II. Hence, the masses are more likely bilateral vestibular shwannoma. The embryological origin of shwannomas is the neural crest. Educational Objective: The neural crest is the embryological origin of shwannomas. |
Approved | Approved::Yes |
Keyword | WBRKeyword::Embryology, WBRKeyword::Neural crest, WBRKeyword::Schwannoma, WBRKeyword::Brain tumor, WBRKeyword::Cancer, WBRKeyword::Neurofibromatosis |
Linked Question | Linked:: |
Order in Linked Questions | LinkedOrder:: |