Case Study 27
Download
Report
Transcript Case Study 27
Case Study 27
Julia Kofler, M.D.
Question 1
A 5-year-old girl presents with a ~6 week history of early
morning headaches. Describe the findings in her MRI
scan.
T1
T1 plus
contrast
T1 plus
contrast
Answer
Large mixed cystic and solid midline mass in the
posterior fossa
Inhomogeneous contrast-enhancement of the solid
component
Mass effect with displacement of the brainstem
Obstructive hydrocephalus
Question 2
What is your major differential diagnosis for posterior
fossa tumors in children?
Answer
Ependymoma
Pilocytic astrocytoma
Medulloblastoma
Question 3
An intraoperative consultation was requested and
performed via telepathology. Describe the findings in the
intraoperative smear preparation on the following
representative snapshots obtained via the telepathology
system.
Answer
Hypercellular smear
“Small round blue cells” with scant cytoplasm, finely
speckled chromatin and inconspicuous nucleoli
No glial processes apparent
Numerous mitotic figures and apoptotic bodies
Question 4
What is your intraoperative diagnosis?
Answer
Medulloblastoma
Question 5
A resection of the mass was performed. Describe the
findings in the following representative permanent H&E
slide.
Click here to view slide.
Answer
Densely packed round to oval cells with high N/C ratio,
scant cytoplasm and inconspicuous nucleoli
Occasional nuclear molding
Frequent apoptotic cells and scattered mitoses
Multiple foci of necrosis
Scattered Homer Wright rosettes
Large areas with a nodular appearance; nodules
display decreased cellular density, reduced N/C ratio
and a fibrillary matrix
No anaplastic features are present
Question 6
Identify the rosette types in the following images and give
example(s) of tumors where these rosettes can be found.
A
Image sources:
Ellison and Love, Neuropathology, 2nd ed, 2007
Wippold and Perry, Am J Neuroradiol 2006; 27:488-492
B
C
D
Answer
A. Pseudovascular pseudorosette: Ependymoma,
glioblastoma, medulloblastoma, PNET, pilomyxoid
astrocytoma
B. Flexner Wintersteiner rosette: Retinoblastoma,
pineoblastoma
C. Ependymal rosette: Ependymoma
D. Homer Wright rosette: Neuroblastoma,
medulloblastoma, PNET, pineoblastoma
Question 7
Medulloblastomas can present with distinct
histopathologic subtypes.
1)Name major histopathologic subtypes
2)Which is the predominant subtype in our case?
3)Which stains can be used to highlight this growth
pattern in our case?
Answer
1) - Desmoplastic/nodular medulloblastoma
- Medulloblastoma with extensive nodularity
- Anaplastic medulloblastoma
- Large cell medulloblastoma
- Medulloblastoma with myogenic differentiation
- Medulloblastoma with melanotic differentiation
2) Desmoplastic/nodular medulloblastoma
3) Synaptophysin, reticulin, Ki-67
Question 8
Describe the findings in the following
immunohistochemical slides for synaptophysin and Ki-67.
Click here to view slide
(GT.59B synaptophysin, GT.59C Ki-67).
Answer
Synaptophysin is positive within the nodular areas
indicating regions of neuronal maturation
Ki-67 shows high proliferative activity in the
internodular areas and lower proliferation rates within
the nodules
These stains support a diagnosis of
desmoplastic/nodular medulloblastoma
Question 9
Name clinical, pathological and molecular factors that
have been associated with adverse or favorable outcome
of medulloblastomas.
Answer
Adverse outcome:
Age <3 years
Incomplete surgical resection
Metastatic disease
Large cell/anaplastic variant
Isochromosome 17q, loss of 17p, amplification of
MYCC or MYCN genes
Favorable outcome:
Desmoplastic/nodular variant
Nuclear accumulation of beta-catenin
Question 10
Which familial cancer predisposition syndrome is
associated with the desmoplastic/nodular variant of
medulloblastoma?
Answer
Naevoid basal cell carcinoma syndrome (Gorlin
syndrome)