Case Study - University of Pittsburgh

Report
Case Study 1
Harry Kellermier, M.D.
Question 1
This is a 70 year-old male who presented with
paresthesias and clumsiness in his right upper
extremity. What are the abnormal findings seen in these
radiographs?
Answer
 Mass lesion
 In the left frontoparietal region
 Irregular
 Peripherally enhancing
 Surrounding edema
Question 2
What is your differential from these radiographs?
Answer
Malignant glioma; Metastasis; Lymphoma; Abscess;
Subacute infarct.
Question 3
EXAMINE SMEAR. An intraoperative consultation was
requested. Describe the microscopic findings on this
slide.
Click here to view slide
Answer
 Reactive astrocytes with abundant eosinophilic
cytoplasm
 Background acute and chronic inflammatory cells
 Macrophages
 Vessels with plump, reactive endothelium
Question 4
What would the intraoperative consultation be based on
the previous smear? (A: Category such as Defer,
Reactive, or Neoplastic; B: More specific diagnosis)
Answer
 Defer
 Reactive and inflammatory changes
Question 5
EXAMINE H&E. The permanent section from the
intraoperative specimen has returned from
histology. Describe the microscopic findings on this slide.
Click here to view slide.
Answer
 Fibrovascular tissue
 Necrotic tissue
 Inflammatory infiltrate consisting of acute and chronic
inflammatory cells
 Macrophages
Question 6
What additional studies would you like based on this
permanent specimen.
Answer
 GMS
 Gram stain
 Check microbiology results
Question 7
EXAMINE GRAM STAIN: What do you see on this slide?
Click here to view slide.
Answer
Slender, branching gram positive rods
Question 8
EXAMINE GROCOTT STAIN. What do you see on this
slide?
Click here to view slide.
Answer
Filamentous, branching rods
Question 9
What organisms are in your differential?
Answer
 Nocardia
 Actinomyces
 Streptomyces
Question 10
What additional stain would you order (pictured below)?
A.Ziehl-Nielsen
B.Fite
C.Luxol Fast Blue
D.Warthin-Starry
E.Modified Gram Stain
Answer
The answer is B. Fite.
Question 11
By what route of infection did this patient acquire
Nocardia?
Answer
Nocardia species are widely distributed in the environment. The
usual route of infection is by inhalation and pulmonary involvement,
with subsequent spread to other sites. Nocardia asteroides complex
accounts for approximately 80% of cases of noncutaneous invasive
disease. According to some reports, the CNS is the second most
commonly affected organ with some studies citing secondary CNS
involvement in approximately 25% of cases. Despite this apparent
affinity for the CNS, Nocardia accounts for only approximately 2% of
all brain abscesses. Patients who develop nocardial brain abscesses
are typically immunosuppressed. Commonly affected groups include
organ transplant recipients, persons with connective tissue diseases,
HIV, pulmonary diseases and underlying malignancies. Less
commonly, Nocardia may present as a meningitis, diffuse cerebral
infiltration, or granulomas.
Epidemiology
 0.3-1.3 per 100,000 people per year
 Higher in immunocompromised patients
 Causative organisms
 Streptococcus species- 34%
 Viridans 13%, pneumoniae 2%
 Staphylococcus species- 18%
 Aureus 13%, epidermidis 3%
 Gram negative enteric- 15%
 Proteus 7%
 Klebsiella, E.Coli, enterobacteriae all 2%
 Nocardia- 1%
Distribution of causative
microorganisms through time
Predisposing conditions
 Otitis/mastoiditis- 32%
 Sinusitis- 10%
 Hematogenous- 13%
 Meningitis- 6%
 Postoperative- 9%
 Unknown- 19%
Location
 81% of the time only a single lesion was identified
 Frontal lobe- 31%
 Temporal lobe- 27%
 Parietal lobe- 20%
 Cerebellar and brainstem- 13%
Diagnosis and outcome
 Aspiration with culture and smear!
 MRI>CT scan
 DWI hyperintense signal with correlating hypointense
signal on ADC had a 96% sensitivity and specificity for
differentiating abscess from other intracranial cystic mass
 Outcome
 20% Mortality
 57% Good outcome
References
 Brouwer et al. ‘Clinical characteristics and outcome of
brain abscess: Systemic review and meta-analysis.’
Neurology, 1/29/2014

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