CNS Tumors (NEURO)

CNS Tumor presentation key concepts

clinical presentation of CNS tumors

may be focal or generalized seizures, focal neurologic deficits, signs of ICP

CNS tumors

invasion and destruction of vital centers with prognosis related to benign or malignant behavior

extra cranial metastasis

rare complication of CNS tumors where the brain has no lymphatics that may spread along the subarachnoid space

glial cells

astrocytes, ependymal cells, and oligodendrocytes that produce most primary CNS tumors

gliomas

more common in males, include astrocytomas I-IV, ependymoma, and oligodendroglioma

astrocytoma grade I

AKA pilocytic astrocytoma, does not infiltrate, rarely progresses to a higher grade, and has both a better prognosis and distinct differences from other astrocytomas

pilocytic astrocytoma

well-circumscribed mural nodule associated with a cyst, has compact and microcystic areas with cells containing piloid hairlike processes

astrocytoma grades II-IV

diffusely infiltrative growth pattern into white matter, poorly demarcated, and most have a dense meshwork of cytoplasmic processes

astrocytoma grade II

astrocytoma that presents with pleomorphism

anaplastic astrocytoma grade III

astrocytoma that shows mitoses 

glioblastoma grade IV

marked vascular proliferation with production of VEGF, hemorrhage, necrosis, pseudo palisading pattern of cells in the tumor

oligodendroglioma

diffuse infiltrate cortex, uniform cells with perinuclear halos and round nuclei, branching capillaries

ependymoma

often grown near ependymal-lined ventricles or spinal cord central canal, usually present 

myxopapillary ependymoma

in filum terminale of spinal cord, cuboidal cells around papillary cores in myxoid background

subependymoma

grade I tumor, slow-growing may form a small calcified lesion, high fibrillar background with low cellularity 

medulloblastoma

high malignant and poorly differentiated, seen in the cerebellum in the midline in children and the lateral aspects in adults, CSF spread is common

primitive neuroectodermal tumors (PNET)

similar tumors to medulloblastoma but seen in other locations

homer-wright rosettes

histological pattern of tumor cells in medulloblastoma’s, arranged in a circular formation around a central core of delicate fibers, known as neuropil

Flexner-Wintersteiner rosettes

characteristic structures found in medulloblastomas that are formed by tumor cells arranged in a circle around a central lumen

meningiomas

most common extra-axial tumor that arise from arachnoid cap cells, slow growing dural based mass association with hyperostosis of overlying skull

hemangioblastomas

CNS manifestations of von Hippel-Lindau disease, autosomal dominant on chromosome 3P, mixture of delicate capillary vessels and stroma cells with multiloculated cytoplasms

choroid plexus neoplasms

papillary neoplasms, solid areas with necrosis and mitoses

schwannoma

benign encapsulated tumor arising from schwann cells, associated with sensory nerves

intracranial schwannoma

acoustic neuroma of CNVIII and CNV

spinal schwannoma

posterior sensory roots

antioni A

dense region in spindle cell tumor schwannoma

antoni B

loose region in spindle tumor schwannoma

verocay bodies

key histologic feature of schwannoma chracterized by the alignment or palisading of nuclei

neurofibromatosis type 1

chromosome 17, multiple neurofibromas and pilocytic astrocytomas

neurofibromatosis 2

chromosome 22, neoplastic proliferation of Schwann cells, fibroblasts, and perineurial-like cells causing expansion of nerve

MISME

multiple inherited schwannomas, meningiomas, and ependymomas

Germ cell tumors

Arise from the transformation of primordial tissue derived from ectoderm, mesoderm, or endoderm. Features resemble seminoma in the testis and dysgerminoma in the ovary

Primary CNS lymphoma

Non-Hodgkin’s lymphoma: usually of B cell origin, soft gray pink-with areas of necrosis and hemorrhage

Metastatic tumors

Spread via the hematogenous route is most common since the brain lacks lymphatics. Spinal cord spread does involve lymphatics

CNS metastasis

Headache focal neurological signs and symptoms common, papilledema, seizures

Hemorrhagic mets

Lung carcinoma: adenocarcinoma and small cell carcinoma are more common than squamous carcinoma, Melanoma, Choriocarcinoma, Renal cell carcinoma