Embryonal Tumors Flashcards
A 4-year-old patient presents with history of nausea, vomiting, headache, lethargy, and irritability which developed during the course of 6 to 10 weeks. CT of brain showed a hyperdense contrast-enhancing mass in the posterior fossa with calcifications while MRI showed hypo- to isointense lesion on T1,
heterogenous lesion on T2. A diagnosis of medulloblastoma (grade 4) tumor is made. Where does this tumor arise in the posterior fossa most commonly?
● A. Floor of the fourth ventricle near fastigium
● B. From the roof of the fourth ventricle
● C. In the cerebellum, they arise in the vermis near the apex of the roof of the fourth ventricle
● D. In the cerebellum, these arise from cerebellar hemisphere
● E. From the floor of the fourth ventricle near the foramen of Magendie
C. In the cerebellum, they arise in the vermis near the apex of the roof of the fourth ventricle
Medulloblastomas which were formerly called as primitive neuroectodermal tumors (PNET) are now considered under umbrella term embryonal tumors and account for 68% of embryonal tumors. About 10 to 35% of these tumors are seeded to spinal canal at the time of diagnosis and warrants imaging of
the entire neuraxis. Which statement is correct regarding treatment of these tumors?
● A. Invasion or attachment to the floor of the fourth ventricle at the brainstem in the region of facial colliculus often limits its excision
● B. Opening of foramen magnum with removal of C1 and C2 arches is often required for midline cerebellar medulloblastomas
● C. 30 to 40% of children require permanent VP shunt postoperatively
● D. Postoperative radiotherapy (54 gray to primary tumor and 18 gray to craniospinal axis) and chemotherapy are needed in almost all patients
● E. All of the above
E. All of the above
Which statement is incorrect regarding poor prognosticators of medulloblastoma?
● A. Poor Karnofsky performance scale score
● B. Inability to perform gross total resection
● C. MDB classification with SHH activated, TP53 wild type with classic histology
● D. Disseminated disease at the time of diagnosis
● E. Younger age of patient for some cell types (< 3 years)
C. MDB classification with SHH activated, TP53 wild type with classic histology
Which of the following is the most common histologic variant of medulloblastoma which constitutes 72% of medulloblastomas, is predominant in children, is found in all four molecular medulloblastomas, is composed of densely packed undifferentiated small round cells with mild-to-moderate nuclear pleomorphism, and has high mitotic count?
● A. Classic type
● B. Desmoplastic/nodular
● C. MDB with extensive nodularity
● D. Large cell/anaplastic MDB
● E. Both A and B
A. Classic type
A patient is found to have medulloblastoma (MDB) around the foramen of Luschka, arising from the brain stem on imaging. These MDBs account for 15% of adults MDBs with male to female ratio of 1:2 with predominant histologic variant of classic type. In spite of being grade 4, the prognosis for children is
excellent with surgery and adjuvant therapy in contrast to poor prognosis in adults. Which molecular type of MDB is this?
● A. WNT activated
● B. SHH activated TP53 wild type
● C. SHH activated TP53 mutant
● D. MDB non-WNT/non-SHH
● E. Group 4 MDB
B. SHH activated TP53 wild type
Putative cell of origin of SHH activated, TP53 wild type MDB is cerebellar granule neuron cell precursors of the external granule cell layer and cochlear nucleus. What is the predominant histologic variant in SHH activated, TP53 wild type MDB?
● A. Extensive nodularity
● B. Classic
● C. Large cell/anaplastic
● D. Desmoplastic/nodular
● E. Both A and B
D. Desmoplastic/nodular
SHH activated, TP 53 mutant MDB is mostly a high-risk tumor. What is the most common histologic variant in these tumors?
● A. Extensive nodularity
● B. Classic
● C. Large cell/anaplastic
● D. Desmoplastic/nodular
● E. Both A and B
C. Large cell/anaplastic
Atypical teratoid or rhabdoid tumors are WHO grade 4 embryonal tumors that occur primarily in infants and children. Where in the CNS this tumor can be found?
● A. Cerebral hemispheres
● B. Suprasellar region
● C. Cerebellar hemispheres
● D. Brainstem
● E. Anywhere along the neuraxis
E. Anywhere along the neuraxis
Cribriform neuroepithelial tumors are embryonal tumors that are highly cellular and characterized by presence of cribriform strands and ribbons. What is the location of these tumors?
● A. Brainstem
● B. Cerebellum
● C. Cerebellopontine angle
● D. Near any of the ventricles (third, fourth, or lateral)
● E. Anywhere along the neuraxis
D. Near any of the ventricles (third, fourth, or lateral)
Embryonal tumor with multilayer rosettes is a WHO grade 4 aggressive tumor with mean overall survival of 12 months. This tumor is most commonly found in cerebral hemispheres. Which age group does this tumor affects?
● A. 5 to 10 years
● B. 10 to 14 years
● C. Less than 4 years
● D. After 50 years
● E. None of the above
C. Less than 4 years
A child presented with obstructive hydrocephalus. Which of the following is false regarding medulloblastoma?
● A. CT: noncontrast—typically hyperdense and most lesions enhance with contrast
● B. MRI: T1WI—hypo- to isointense
● C. MRI: T2WI—heterogeneous due to tumor cysts, vessels, and calcifications
● D. MRS: decreased choline and elevated NAA
● E. Spinal imaging: MRI with IV gadolinium or CT/myelography with water-soluble contrast should be done to rule out drop mets
D. MRS: decreased choline and elevated NAA
What is the 5-year event-free survival (EFS) of very high-risk group of medulloblastoma based on histology and molecular profiling?
● A. > 90%
● B. 75–90%
● C. 50–85%
● D. < 50%
D. < 50%
Gross nodular seeding in cerebellar subarachnoid space is designated as which stage in postoperative staging system?
● A. m0
● B. m1
● C. m2
● D. m3
● E. m4
C. m2
Regarding histological/morphological variants of medulloblastoma, what is the most common variant?
● A. Classic
● B. Large cell
● C. Nodular
● D. With extensive nodularity
● E. Anaplastic
A. Classic
Regarding histologic/morphologic variants of medulloblastoma, which of the following is associated with Gorlin syndrome in early childhood?
● A. Classic
● B. Large cell
● C. Nodular
● D. With extensive nodularity
● E. Anaplastic
C. Nodular
