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Lecture 20
Tumors of the Nervous System
Question | Answer |
---|---|
(T or F) In children, CNS tumors are the third most common maliganancy. | False. CNS tumors are the second most common malignancy in children. |
Where are majority of CNS tumors located in the pediatric population? | 60-70% are located in the infratentorial regions such as the cerebellum and brainstem. |
Where are majority of CNS tumors found in the adult population? | 70% are located in the supratentorial region (cerebral hemispheres). |
What types of CNS tumors are Neurofibromatosis type 1 patients at increased risk for? | (1) Neurofibroma (2) Optic nerve glioma (3) Meningioma (4) Malignant peripheral nerve sheath tumor (MPNST) |
What types of CNS tumors are Neurofibromatosis type 2 patients at increased risk for? | (1) Bilateral vestibular schwannoma (2) Peripheral schwannoma (3) Meningioma (4) Ependymoma |
What type of CNS tumor are Tuberous Sclerosis patients at increased risk for? | Subependymal Giant Cell Astrocytoma (SEGA) |
What type of CNS tumor are Von Hippel-Lindau patients at increased risk for? | Hemangioblastoma |
What type of CNS tumor are Li-Fraumeni syndrome patients at increased risk for? | Gliomas |
What type of CNS tumor are Gorlin patients at increased risk for? | Medulloblastoma |
What types of CNS tumors are Turcot patients at increased risk for? | (1) Medulloblastoma (2) Glioblastoma |
What type of CNS tumor are Cowden disease patients at increased risk for? | Dysplastic gangliocytoma of the cerebellum |
What type of CNS tumor are Rhabdoid tumor predisposition syndrome patients at increased risk for? | Atypical Teratoid/Rhabdoid Tumor |
What type of CNS tumor are MEN type 1 patients at increased risk for? | Pituitary adenoma |
What types of CNS tumors are associated with ionizing radiation exposure? | (1) Meningiomas (2) Gliomas (3) Maignant nerve sheath tumors |
(T or F) Meningiomas have a higher incidence in men than women. | False. Meningiomas are more common in women than men (2:1) |
(T or F) Gliomas have a higher incidence in men than women. | True. Gliomas are more common in men than women (3:2). |
Virus associated with Primary CNS lyphoma in immunocompromised patients | EBV |
Most common clinical presentation of CNS tumors | (1) Epilepsy (2) Focal neurological signs (3) Signs of elevated ICP (Headache, vomiting, confusion, papilledema) (4) symptoms of hydrocephalus (Headache, nausea, vomiting, decreased conscioussness, abnormal enlargement of head in infants). |
Symptoms and signs of increased ICP | (1) Headache (2) Vomiting (3) Confusion, decreased consciousness, and coma (3) Papilledema |
(T or F) Majority of CNS grow by expansion with defined tumor-brain borders. | False. Majority of CNS tumors grow by infiltrative growth with individual tumor cell invasion of brain structures. |
CNS tumor associated with a "butterfly lesion" | Glioblastomas |
Modes of tumor spread | (1) Along white matter tracts (2) Along pial membrane (3) Along perivascular space (Virchow-Robin) (4) Across ependyma and ventricular lining |
(T or F) Extraneural metastases of CNS are extremely rare. | True. Malignant tumors have been reported to metastasize after operative procedures. |
The most common CNS tumor in all age groups | Gliomas represent approximately 45% of all CNS tumors. |
WHO grade for a glioblastoma | WHO grade IV. It is the most malignant glioma in adults with a poor prognosis. Aver survigial is 12-15 months. |
Common location of pilocytic astrocytomas | Midline sturctures such as the cerebellum, optic nerve and chiasm, 3rd ventricle region/hypothalamus, and brainstem |
Peak age of onset of pilocytic astrocytomas | 10-12 years. One of the most common tumors in children. |
Type of pilocytic astrocytoma characteristic of Nuerofibromatosis type 1 (NF1) | Optic nerve glioma |
Treatment of pilocytic astrocytomas | Typically can be treated with surgical resection; however, tumors located in the 3rd ventricle/hypothalamus region may benefit from radiation and chemotherapy. |
Four histopathological features used for grading malignancy of diffuse astrocytomas | AMEN criteria: A (Atypia), M (Mitoses), E (Endothelial proliferation), N (necrosis) |
Based on the AMEN criteria, what are the positive malignant features of Astrocytomas? | Atypia |
(T or F) Diffuse infiltrating astrocytomas are more common in adults than children. | True. Typically present during the 5th to 7th decade of life. |
Based on the AMEN criteria, what are the positive malignant features of Anaplastic Astrocytoma? | (1) Atypia (2) Mitotic activity |
Based on the AMEN criteria, what are the positive malignant features of Glioblastoma? | (1) Atypia (2) Mitotic activity (3) Necrosis and/or (4) Endothelial proliferation |
Define secondary glioblastoma | A tumor progressing from a lower grade astrocytoma (grade II or III) |
Age of diagnosis of Primary Glioblastoma versus Secondary Glioblastoma | Primary Glioblastoma: 55-60 years and Secondary Glioblastoma: 40 years |
(T or F) Majority of glioblastoma cases are primary glioblastomas. | True. 95% of cases are primary glioblastomas. |
Typical location of Oligodendrogliomas | Supratentorial areas, most commonly frontal and temporal lobe |
Clinical presentation of Oligodendrogliomas | The great majority of oligodendrogliomas have a slow clinical evolution and is associated with a long history of seizures. |
Peak age of incidence of Oligodendrogliomas | 4th and 5th decade |
Type of CNS tumor commonly found in the frontal and temporal lobe and associated with a long history of seizures. Characteristic neuroimaging features include frequent micro and macrocalcifications. | Oligodendrogliomas |
(T or F) Oligodendrogliomas without chromosomal deletion of 1p and 19q have a better prognosis than Oligodendrogliomas with 1p/19q chromosomal deletions. | False. Oligodendrogliomas with 1p/19q chromosomal deletions respond better to chemotherapy and longer disease-free time after chemotherapy. Patients survive longer. |
Genetic abnormality associated with Oligodendrogliomas | The most common genetic alteration associated with Oligodendrogliomas are 1p/19q chromsomal deletions. |
Common histologic features of CNS embryonal tumors | (1) High cellularity (2) Primitive-appearing small cells (3) High mitotic activity |
Duration of symptoms to diagnosis of Primary Glioblastoma versus Secondary Glioblastoma | Primary Glioblastoma has a short clinical presentation with an average of 1.7 months. Secondary Glioblastoma progresses from a lower grade astrocytoma with an average duration of symptoms to diagnosis of greater than 25 months. |
WHO grade for CNS embryonal tumors | WHO grade IV |
Types of CNS embryonal tumors | (1) Medulloblastomas (2) CNS Primitive Neuroectodermal Tumors (Medulloepithelioma and Ependymoblastoma) (3) Atypical Teratoid/Rhabdoid Tumor |
(T or F) CNS embryonal tumors have a high tendency for cerebrospinal fluid seeding. | True |
Most common CNS embyronal tumor | Medulloblastoma |
Most common location of Medulloblastomas | Cerebellum |
Genetic alterations associated with Medulloblastomas | (1) Isochromosome 17q (2) Loss of chromosome 17q in a different locus than TP53 (3) Amplification of c-myc |
CNS tumor arising from meningothelial cells. May occur sporadically or in asociation with Neurofibromatosis type 2. | Meningiomas |
(T or F) There is an high association with Meningiomas with Neurofibromastosis type 2 in childhood. | True. Approximately 40% of children with meningiomas have Neurofibromatosis type 2. |
Gender predilection of Meningiomas in adults | Marked female predominance (3:1) |
Common location of Meningiomas | (1) Convexity of cerebral hemispheres (2) Parasagittal regions (2) Skull base (3) Sphenoid wing (4) Spine |
Common symptoms of Meningiomas | Seizures and focal deficits are common symtpoms of Meningiomas. These tumors are extra-axial tumors and tend to compress the underlying brain/spine parechyma. |
Meningioma variants with WHO grade III classification | These tumors are classified as malignant: Rhabdoid, Papillary, and Anaplastic |
Meningioma variants with WHO grade II classification | WHO grade II tumors tend to recur. (1) Chordoid (2) Clear cell (3) Atypical |
Extranodal non-Hodgkin's lymphoma arising in the CNS in the absence of obvious lymphoma outside the nervous system. | Primary CNS lymphomas |
Common location of Primary CNS Lymphomas | (1) Supratentorial areas (deep white matter) (2) Periventricular regions (3) Basal ganglia (4) Posterior fossa |
(T or F) Primary CNS Lymphomas are unlike most primary CNS tumors because the lesions are often multiple and multifocal, simulating metastatic tumor. | True. Multiple lesions are particulary prevalent in the AIDS and post-transplantation population. |
Most common subtype of Primary CNS Lymphomas | Large B-cell lymphomas |
Virus associated wtih Primary CNS Lymphomas in immunocompromised patients | EBV |
Subtype of pituitary adenoma characterized by amenorrhea and galactorrhea | Prolactin-secreting adenomas (Prolactinomas) |
Subtype of pituitary adenoma characterized by acromegaly and/or gigantism | GH-Secreting adenoma (Somatotrophinomas) |
Subtype of pituitary adenoma manifesting as Cushing's disease | ACTH-secreting adenomas (Corticotrophinomas) |
Clnically non-functional adenomas | (1) Gonadotrophinomas (2) Silent adenomas (3) Null-cell adenomas |
Signs and symptoms of Clnically non-functional adenomas | Most Clnically non-functional adenomas present with signs and symtpoms of a tumor mass growing and compressing the sellar structures: headaches, visual loss, hypopituitarysm. |
5-year survival of Pituitary adenomas | 78.1% |
Most common intracranial tumor | Metastatic tumors of the CNS |
Most common location of Metastatic tumors of the CNS | 80% of brain metastases are located int he arterial border zones of cerebral hemispheres (cortical-white matter junction), 15% in cerebellum, and 3% in basal ganglia |
Most common primary tumor site of intracranial CNS metastases | Lung (50%) |
Most common primary tumor sites of intracranial CNS metastases | (1) Lung-50% (2) Breast-15% (3) Skin/Melanoma-11% (4) Unknown primary site-11% |
Most common primary tumor site of intraspinal CNS metastases | Breast (22%) |
Most common primary tumor sites of intraspinal CNS metastases | (1) Breast-22% (2) Lung-15% (3) Prostate-10% (4) Malignant lymphomas/leukemias-10% |