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Q&A about PA - Richard A. Fradera González

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Q&A about PA - Richard A. Fradera González

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A 7-year-old boy is brought to the clinic by his parents due to progressive headaches, nausea, and occasional vomiting over the past two months. His parents also note that he has become more clumsy and has had difficulty walking steadily. On physical examination, he has dysmetria on finger-to-nose testing and an ataxic gait. MRI of the brain reveals a well-circumscribed cystic mass with an enhancing mural nodule located in the cerebellum. Histopathologic examination of the lesion shows Rosenthal fibers.

Which of the following is the most likely diagnosis?

A. Pilocytic astrocytoma
B. Medulloblastoma
C. Ependymoma
D. Craniopharyngioma
E. Glioblastoma multiforme

Right Answer: A

REMEMBER: Pilocytic Astrocytoma (PA) is characterized by presenting a histopathologic result showing Rosenthal fibers. Also, the patient is a child, and in children PA is most of the times located in the cerebellum, while in adults is mostly located in the cerebrum.

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A 42 year old man presents to neurology consult after presenting his first seizure. His wife reports he had a brief episode of staring and lip smacking, followed by confusion lasting several minutes. Over the past months he has been more irritable and his wife comments he isn't acting like himself.

A stereotatic biopsy is performed, and histological examination shows a fried egg appearance. MRI shows a calcified mass in the frontal lobe.

What cell type is most likely affected?

A. Gastrointestinal

B. Oligodendrocytes

C. Ependymal Cells

D. Purkinke Cells

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A 4 year old boy presents to the clinic with persistent, painful headaches. A head/brain scan is performed. The scan indicates a developing mass in a specific cell. From which cells do Medulloblastomas originate?

A) oligodendrocytes

B) Schwann cells

C) Astrocytes

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Question like exam:

1. A 6-year-old boy is brought to the pediatrician by his parents due to frequent falls and difficulty walking over the past few months. They report that he has also been complaining of morning headaches and nausea that improve as the day progresses. On examination, he has truncal ataxia and difficulty performing finger-to-nose testing. Fundoscopic exam reveals papilledema. MRI of the brain shows a hyperdense mass in the cerebellar vermis that is compressing the fourth ventricle, causing obstructive hydrocephalus. A biopsy of the mass shows small, round blue cells with Homer-Wright rosettes.

Question:

Which of the following is the most likely complication associated with this tumor?

A) Hemorrhagic metastases to the lungs

B) Spinal metastases causing cauda equina syndrome

C) Optic nerve compression causing blindness

D) Pituitary dysfunction leading to growth hormone deficiency

E) Cerebral herniation leading to death

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Question:

A 7-year-old boy presents with signs of increased intracranial pressure and imaging reveals a mass in the posterior fossa near the 4th ventricle. Histological examination shows Homer-Wright rosettes and neuroectodermal tissue with abundant dark-staining nuclei. What is the most likely diagnosis, and which genetic mutation is commonly associated with this tumor?

Answer Choices:

A) Pilocytic astrocytoma; BRAF mutation

B) Medulloblastoma; ERBB2 mutation

C) Ependymoma; NF2 mutation

D) Craniopharyngioma; CTNNB1 mutation

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Figure 1. MRI showing meningioma in the right parietal lobe. (Cohen-Gadol, A. 2024)

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1. Location:

1. Cerebral convexities or along the skull base along the dorsum of the spinal cord

2. Histology:

1. Psammona Bodies (round shape laminated calcifications)

3. Cells Involved:

1. Arachnoid Cell

4. Clinical Features:

1. Headaches

2. Seizures

3. Neurological deficits

5. Genes involved:

1. Until today, there are still no reports of genes involved in meningiomas.

6. Tumor markers:

1. Ki-67 = most important for recurrence

2. EMA + Vimentin = classic immunostains for diagnosis

3. PR = may suggest slower growth

4. SSTR2A = useful for imaging & experimental treatments

7. Prevalence:

1. Most common in patients > 65 years of age. Tend to be more common in women, in patients with Neurofibromatosis type 2, and those with a past medical history of cranial irradation

8. Extra:

1. WHO grade I meningiomas: good prognosis, with a 5-year recurrence rate of 7–23% after resection

2. WHO grade II and III meningiomas: poor prognosis, with a 5-year recurrence rate of ∼ 50% and ∼75%respectively after resection

3. Ki-67 index: an indirect measure of the rate of tumor growth

MIB-1 is a monoclonal antibody used to assay the antigen Ki-67 (a nuclear protein seen in proliferating cells).

Ki-67 index > 4% is associated with a higher meningioma recurrence rate.

2. Associated syndromes:

1. Neurofibromatosis

2. Gordin Syndrome Cowden

References:

1. Aaron Cohen-Gadol, M. D. (2024, October 12). Meningioma y cáncer: Cirujano Experto. Meningioma y cáncer | Cirujano experto | Aaron Cohen-Gadol, MD. https://www.aaroncohen-gadol.com/es/pacientes/meningioma-es/historia-natural/cancer-y-meningioma

2. Meningiomas. Next.amboss.com. (n.d.-d). https://next.amboss.com/us/article/I30YPf?q=Meningioma

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Karina Hernandez, Andrea Ozaeta, Dionel Rodríguez Rivera, Allison Rodríguez Medina, Richard Fradera González

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Alexandra Kalo, Antonella Giosa, Nicole Pérez, Seth Eifler, Daniel Scott, Ariel Álvarez, Isaacs Figueroa Rodríguez, Juan Alejandro Morciego Díaz.

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Figure 1. Pilocytic Astrocytoma diagnoses using MRI and macroscopic pathology techniques. (Clarke, C. 2022.)

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1. Location:

1. Posterior fossa > Cerebellum in children

2. Cerebrum in adults

2. Histology:

1. Rosenthal fibers

2. Eosinophilic intracytoplapmic inclusions

3. Eosinophilic granular bodies

3. Cells Involved:

1. Astrocytes

4. Clinical Features:

1. Vomiting

2. Ataxia

3. Failure to thrive

4. ICP

5. Genes involved:

1. GFAP+

6. Tumor markers:

1. GFAP gene

2. KIAA1549-BRAF

3. BRAF gene

7. Prevalence:

1. Childhood (9 to 10 years of age) and young adults (<20)

8. Extra:

1. Good prognosis:

1. 5-year survival >90%

2. Rarely progress into a higher grade neoplasm

References:

1. Clarke, C. (2022). Neurooncology. In Neurology - A Clinical Handbook (First, pp. 166–169). essay, John Wiley & Sons Ltd.

2. Collins VP, Jones DT, Giannini C. Pilocytic astrocytoma: pathology, molecular mechanisms and markers. Acta Neuropathol. 2015 Jun;129(6):775-88. doi: 10.1007/s00401-015-1410-7. Epub 2015 Mar 20. PMID: 25792358; PMCID: PMC4436848.

3. (2020). Amthor F.R., & Theibert A.B., & Standaert D.G., & Roberson E.D.(Eds.),Essentials of Modern Neuroscience. McGraw Hill. https://accessmedicine.mhmedical.com/content.aspx?bookid=2938&sectionid=24798737

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Karina Hernandez, Andrea Ozaeta, Dionel Rodríguez Rivera, Allison Rodríguez Medina, Richard Fradera González

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Each group will be given two different type of tumors to investigate. They will then present their findings in the form of a table. The different findings should include: Location, histology, cell of origin, clinical features, genetic factors, tumor markers, prognosis, prevalence, and associated syndromes/illnesses. Review and discuss the findings, using comments to ask questions or provide insights.