Transcript Case Study 16 - University of Pittsburgh

Clayton Wiley MD/PhD
Question 1
46-year-old male with mental status change and rightsided hemiparesis.
Describe the MRI findings (location, enhancement,
mass effect).
Axial T1 pre and post contrast
Axial T2/ FLAIR/ T1 post-contrast
Question 2
Give a differential diagnosis based on
MRI/ age.
Answer
•
•
•
•
•
Lymphoma
PML
Atypical infection
Glioma
Imaging features are not consistent with toxoplasmosis or
pyogenic abscess (ring-enhancing lesion).
Question 3
Describe the cytologic features of the smear.
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Question 4
What additional history might be ascertained to refine the
differential diagnosis?
Answer
Clinical signs of infection.
Is this patient immunosuppressed, HIV-positive?
Blood analysis?
Was CSF culture/ PCR done?
Question 5
The surgeon tells you that this patient has a known
diagnosis of HIV with a CD4 count of 64. Stereotactic
biopsies of the left cerebral white matter are given to you
on saline moistened Telfa. You perform a smear the tissue
on a glass slide. What is your intraoperative diagnosis?
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Question 6
The surgeon thanks you for your assessment and
indicates that s/he is about to close. At this point,
before leaving the OR/ frozen room, what should you
do?
A.Make sure you have enough tissue for diagnosis
B.Ask the surgeon if s/he has sent sterile tissue for
culture
Question 7
Review the H&E paraffin section and give a microscopic
description.
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Question 8
What can the Neuropathologist due to
further evaluate this lesion?
Question 9
You receive the following immunohistochemical study. What is
you interpretation?
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Question 10
What is your final diagnosis?
Answer
Progressive multifocal leukoencephalopathy (PML)—a
demyelinating opportunistic infection of the CNS caused by the
JC papova virus.
Question 11
What cell of the central nervous system is infected in this
disease?
Answer
The oligodendrocyte shows the cytopathic effect in PML.