Transcript Case Study - University of Pittsburgh

Case Study 36
Henry Armah, M.D., M.Phil.
Question 1
Clinical history: 14-year-old male with history of
persistent headache and vomiting. Describe the abnormal
cranial MRI findings?
Axial T1
Sag T1+C
Answer
Contrast enhancing tumor in the fourth ventricle anteriorly
impinging upon the lower pons, with no discernible
hydrocephalus and no discernible meningeal
enhancement.
Question 2
What are your differential diagnoses based on the
patients’ age and the radiological findings?
Answer
1. Medulloblastoma
2. Atypical teratoid/rhabdoid tumor
3. Ependymoma
4. Choroid plexus carcinoma
5. Pilocytic astrocytoma
Question 3
The neurosurgeon performs a craniotomy with biopsy of
the mass and requested an intraoperative consultation.
Describe the microscopic findings on this smear slide?
Click here to view slide.
Answer
Neoplastic proliferation of round-to-oval pleomorphic
tumor cells with scant cytoplasm, nuclear molding,
scattered mitotic figures and numerous apoptotic bodies.
Question 4
What is your intraoperative diagnosis? (A: Category such
as Defer, Reactive/Non-neoplastic, or Neoplastic; B: More
specific diagnosis or statement)
Answer
A. Neoplasm
B. Medulloblastoma
Question 5
Subsequently, the mass was almost completely excised.
The permanent section has returned from histology.
Describe the microscopic findings on this H&E slide?
Click here to view slide.
Answer
Neoplastic proliferation of densely packed cells with
round-to-oval or carrot-shaped hyperchromatic nuclei
surrounded by scant cytoplasm. The tumor cells
predominantly form sheets with vague areas of HomerWright rosettes. The vast majority of tumor cells show
marked nuclear pleomorphism, nuclear molding, and cellcell wrapping. Mitotic figures, including atypical ones, are
readily identified. Numerous apoptotic bodies are noted.
There is no evidence of nodularity.
Question 6
What additional studies would you need to rule out other
important differential diagnoses and confirm the final
diagnosis in this case?
Answer
GFAP, INI-1, Synaptophysin, Neurofilament, EMA,
CAM5.2, and Ki-67 (MIB-1).
Question 7
What do you see on this GFAP immunostain slide?
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Answer
GFAP is negative in tumor cells, and highlights occasional
entrapped reactive astrocytes.
Question 8
What do you see on this INI-1 immunostain slide?
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Answer
INI-1 is strongly and diffusely positive in the nuclei of
tumor cells.
Question 9
What do you see on this Synaptophysin immunostain
slide?
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Answer
Synaptophysin is focally and weakly positive in tumor
cells.
Question 10
What do you see on this Neurofilament immunostain
slide?
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Answer
Neurofilament is negative in tumor cells.
Question 11
What do you see on this EMA immunostain slide?
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Answer
EMA is negative in tumor cells.
Question 12
What do you see on this CAM5.2 immunostain slide?
Click here to view slide.
Answer
CAM5.2 is negative in tumor cells.
Question 13
What do you see on this Ki-67 (MIB-1) immunostain
slide?
Click here to view slide.
Answer
Ki-67 (MIB-1) is positive in the nuclei of 40-50% of tumor
cells.
Question 14
What is your final diagnosis in this case?
Answer
Anaplastic/Large Cell Medulloblastoma.
Question 15
What is the corresponding WHO grade of this lesion?
Answer
WHO Grade 4.
Question 16
Which of the following cytogenetic abnormality is
associated with this lesion?
A.t (1;13)
B.monosomy 22
C.i (17)q
D.22qE.t (1;13)
Answer
C. i (17)q