Cns tumor rest (2)
Transcript of Cns tumor rest (2)
Pathology of CNS(Tumor of CNS)
DR Naila AwalDepartment of pathology
Neuronal tumor
• Ganglioglioma-• Neoplastic ganglion cells and neoplastic glial component (ganglioglioma)• Grade-WHO I Anaplastic variant rare– WHO grade III (grade II eliminated in 2007)• Age -Children/young adults • Site- common in temporal, parietal, frontal lobes.• MRI-
Solid or cystic or both or cyst /mural nodule variable calcification
• Gross Solid or cystic
• No hemorrhage or necrosis
• Single rounded mass about 5.5 cm in diameter, withsmooth outer surface, slightly lobed with large vessels.
C/S-Homogeneous , yellowish with whitish spots
• M/E-• Hallmark –neoplastic ganglion cells that are identified by:
– Loss of cyto-architectural organization– Abnormal (subcortical) localization– Clustering– Large neurons (cytomegaly)– Coarse peripherally aggregated Nissl substance– Bi- or multinucleated neurons with prominent nucleoli
Poorly differentiated tumor
• Medulloblastoma-• Most common childhood tumor• (#2 after pilocytic astrocytoma of cerebellum)• Grade- IV of IV• Arise from cerebellum & projects into 4th ventricle• May grow rapidly and cause hydrocephalus,• 5% metastasize , commonly to bone• 5 year survival is 75% with surgery/radiation• Highly malignant
• Classification (WHO)
• Gross• Well circumscribed, gray-pink, soft/friable.
well-circumscribedsoft, fleshy tumor with areas of softening & necrosisin the center.
• M/E-• Highly cellular • sheets of anaplastic cells with scanty cytoplasm,• hyperchromatic nuclei, that are often elongated & cresent shaped• Mitoses- abundant• Occasional Homer-Wright rosettes
• Homer-Wright rosettes (groups of tumor cells arranged in a circle around a fibrillary center). Similar rosettes are seen in adrenal neuroblastoma.
• Positive stains• NSE, synaptophysin• Focal GFAP• Molecular / cytogenetics description• Isochromosome (17q) or 17p-• 5-30% overexpress c-myc or N-myc;• C-myc overexpression is associated with poor prognosis
• Differential diagnosis• Lymphoma: diffusely infiltrates CNS until it mixes with normal and reactive
fibrillar cells
• PNET• Ependymoma
• Desmoplasmic/nodular medulloblastoma• nodular b/c of its architecture • desmoplastic because it is permeated by (reticulin) fibers that give it a firm
consistency• M/E-
• round pale nodules of tumor separated by zones of darker tumor cells. The pale nodules are composed uniform round to spindle shaped neuronal-appearing cells which are not as active mitotically as the surrounding darker tumor
• Higher magnification of one the paler tumor nodules showing a population of uniform round to oval cells in apale pink fibrillary background. The cells have a more mature neuronal appearance and are less active mitotically. The surrounding darker tumor cells are more primitive appearing with brisk mitotic activity. Desmoplastic medulloblastoma has a better prognosis than the classic form
• Medulloblastoma with extensive nodularity • M/E-• Low power view numerous pale islands• The nodules are composed of a uniform population of tumor cells. The background
is reticulin-free & rich in neuropil-like tissue. Mitosis is not significantly increased. The cells often show streaming in parallel rows
• Special stain-• Reticulin-rich areas of high cellularity
• Anaplastic Medulloblastoma • M/E-• Highly anaplasticnuclei • with high rate of mitosis & apoptosis. • Primitive looking cellswith nuclear molding.• Some are composed of large cells with rounded vesicular nuclei (i.e. no nuclear molding). • Poor prognosis.
• Atypical teratoid/ Rhabdoid tumor• Highly malignant• Age- very young age (before 5 yrs of age)• Site-Usually posterior fossa or supratentorial• Very aggressive with poor prognosis ( survival <1 yr after
diagnosis)• Metastasizes throughout CSF• MRI-• Large heterogenous mass
• Gross-• Normal cerebellum is visible on right. The unnecessarily large green arrow on
left points sthows Atypical Teratoid/Rhabdoid Tumor (ATRT). • Large, soft in consistency
• M/E-• Large and pleomorphic rhabdoid cells withabundant eosinophilic cytoplasm • Eccentric round nuclei and prominent nucleolus+mesenchymal cell+Epithelial cell+Small cell• Mitosis, necrosis & dystrophic calcification are common
• Positive stainsVimentin, EMA, smooth muscle actin & keratin.
• Negative stainsDesmin, Myoglobin
• D/DPNET/medulloblastoma (no rhabdoid cells, no 22q11 deletions, IN1+,
• Chordoma• Ependymoma• Germ cell tumors
Other parenchymal tumor
• Primary CNS lymphoma• Arise from brain, spinal cord, or leptomeninges without prior or concurrent tumor outside the
CNS• Occurs-• Immunocompromised patients-include HIV/AIDS (most common),after transplantation• Site- usually supratentorial.• Gross-• Solitary or multiple and poorly circumscribed with hemorrhage and ncrosis.• M/E-• Perivascular growth of large atypical lymphoid cells. • With continued proliferation, the distribution becomes more diffuse and sheet-like. • Special stain-• Reticulin stain -Hooping
Metastaic tumor
Peripheral nerve sheath tumor
• Arise form cells of peripheral nerve including schwann cells, perineurial cells & fibroblast.
• Include-• Schwannoma• NEUROFIBROMA
• Schwannoma
• Gross• well, circumscribed , encapsulated mass attatched to nerve• C/s-• G/w cystic &xanthomatous changes.
• M/E-• Biphasic: compact hypercellular Antoni A areas and myxoid hypocellular Antoni B
areas
• Cells , elongate, wavy with tapered ends arranged in fascicle• Nuclear palisading around fibrillary process (Verocay bodies) are often seen in
cellular areas.
• Positive stains•
EMA (capsule), S100 (Schwann cells), calcinurin, laminin, type 4 collagen, vimentin, CD68, GFAP
• Differential diagnosis
• Fibrous histiocytoma• Leiomyoma• Leiomyosarcoma
• NEUROFIBROMA• are peripheral nerve tumors composed of a mixture of Schwann
cells and fibroblasts.• Subtypes
Cutaneous NF: Discrete localized mass Plexiform NF: Growing within & expanding peripheral nerves .
associated with NF1
Cutaneous NF• M/E-• Dermis & s/c fat• Unencapsulated• Interlacing bundles of cells with ovoid-to-spindle, often curved, nuclei• myxoid matrix
non encapsulated proliferation of spindle cells with wavy nuclei, arranged haphazardly in a loose myxoid stroma
• Positive stainsS100, CD34+ (focal), Factor 13a (focal)
• Differential diagnosisMyxoid liposarcoma
Myxoma
• Plexiform NF-• Gross-• Affected nerve is irregularly expanded• Often resembles "bag of worms“
• M/E-• Individual fascicles in a nerve are enlarged due to proliferation of Schwann
cellls and fibroblasts.
showing bundles of nerve fibres arranged in concentric manner with Schwann cells and fibroblasts
• Positive stains• S100 in scattered cells (unlike strong staining in schwannoma)• Perineurial cells are EMA+ in plexiform but not in ordinary neurofibromas
• Differential diagnosisPlexiform schwannoma
Malignant peripheral nerve sheath tumor (MPNST)
• Highly malignant• Locally aggressive, • Involve medium to large size artery• Recurrence• Gross- poorly defined mass
• M/E-• infiltrates nerve and soft tissue with necrosis• marked hypercellularity with spindle-shaped nuclei with tapered ends, nuclear
pleomorphism and brisk mitotic activity with abnormal forms• Patterns: fibrosarcoma, pleomorphic sarcoma,MFH, Schwann cells, triton
tumor (rhabdomyosarcoma regions) and chondrosarcoma
• Positive stainsp53; variable S100
• Differential diagnosisMetastatic MPNST