WBR0304

Author	[[PageAuthor::Mugilan Poongkunran M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Infectious Disease
Prompt	[[Prompt::A 40 year old is brought to the ER by his family member’s with weakness of left upper and lower limbs. On examination, the patient appears confused, temperature is normal, his vitals are stable and other system examination is also normal. His past history is insignificant. A CT scan performed shows a small focal well defined lesion in the right hemisphere. A lumbar puncture is performed, but CSF findings and cytology is inconclusive. HIV ELISA turns positive and his CD4 count is 45/µL. You start the patient on steroids, radiation therapy and HAART therapy. Which of the following is the best prognostic sign for this patient’s condition?]]
Answer A	AnswerA::Decrease in EBV DNA in CSF
Answer A Explanation	[[AnswerAExp::Incorrect : Measurement of Epstein-Barr virus DNA in CSF also provides a surrogate marker to monitor the response to therapy for PCL and not the overall survival prognosis.]]
Answer B	AnswerB::Rapid response to radiation therapy
Answer B Explanation	[[AnswerBExp::Incorrect : Rapid response to radiation therapy and steroids is seen in 30-50% of the patients. However this does not increase the overall survival.]]
Answer C	AnswerC::Increase in CD4 count
Answer C Explanation	[[AnswerCExp::Correct : Initiation of HAART therapy and increase in CD4 count is best prognostic sign as the degree of immunosuppression seems to be the major determinant in these patients.]]
Answer D	AnswerD::Increase in soluble B cell marker in CSF
Answer D Explanation	[[AnswerDExp::Incorrect : Increase in soluble B cell marker in CSF is considered as a diagnostic tool in primary CNS lymphoma.]]
Answer E	AnswerE::Staging of lymphoma
Answer E Explanation	[[AnswerEExp::Incorrect : Staging is of value in only a minority of patients with systemic lymphoma and is generally not indicated in patients with PCL. This disorder almost always remains confined to the central nervous system, but within this space may spread to all compartments including the leptomeninges, spinal cord, and eye.]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::There are currently four AIDS-defining malignancies: Kaposi's sarcoma, non-Hodgkin lymphoma (NHL) of high-grade pathologic type and of B cell or unknown immunologic phenotype, primary CNS lymphoma (PCL), and invasive cervical carcinoma. Primary central nervous system lymphoma (PCL) is an uncommon variant of extranodal non-Hodgkin lymphoma (NHL) that involves the brain, leptomeninges, eyes, or spinal cord without evidence of systemic disease. Educational Objective: References: ]]
Approved	Approved::Yes
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