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COM II- Neuro Robbins > Chap 28 Morphology 4 > Flashcards

Chap 28 Morphology 4 Flashcards

1
Q

What are the characteristics of diffuse astrocytomas?

A

Poorly defined, gray infiltrative tumors that expand and invade the brain

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2
Q

What is always present in a diffuse astrocytoma?

A

Infiltration beyond the outer margins

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3
Q

What is the microscopic appearance of a diffuse astrocytoma?

A
  • Greater cellular density than normal white matter
  • Astrocytic processes
  • Indistinct transition between neoplastic and normal tissue
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4
Q

What are the characteristics of an anaplastic astrocytoma?

A
  • More densely cellular
  • Greater nuclear pleomorphism
  • Mitotic figures present
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5
Q

What is a gemistocytic astrocytoma?

A

A tumor where the predominant neoplastic astrocyte shows brightly eosinophilic cell body

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6
Q

What is the histologic appearance of a glioblastoma?

A
  • Similar to an anaplastic astrocytoma + necrosis and vascular endothelial cell proliferation
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7
Q

What is pseudo-palisading?

A

A histologic pattern where the tumor cells collect along the edges of the necrotic regions

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8
Q

What occurs with vascular cell proliferation in glioblastomas?

A
  • Tuft of cells pile up and create a double layer of endothelial cells
  • Forms a ball-like structure called a glomeruloid bodyt
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9
Q

What is the relevance of VEGF in relation to vascular change in glioblastomas?

A

VEGF is produced by malignant astrocytes in response to hypoxia

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10
Q

What is gliomatosis cerebri?

A

A diffuse glioma with extensive infiltration in the brain

*Considered a grade III/IV lesion

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11
Q

What are the common characteristics of pilocytic astrocytomas?

A

Cystic and usually well circumscribed

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12
Q

What cells are present in a pilocytic astrocytoma?

A

Bipolar cells with long, thin “hairlike” processes that form fibrillary meshworks

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13
Q

What can be a characteristic finding for a pilocytic astrocytoma?

A

Rosenthal fibers and eosinophilic granular bodies

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14
Q

What is a difference between diffuse fibrillary astrocytomas and pilocytic astrocytomas?

A

Pilocytic astrocytomas show limiting infiltration to the surrounding brain whereas diffuse filbrillary astrocytomas do show infiltration

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15
Q

What is the appearance of oligodendrogliomas?

A

Well circumscribed, gelatinous, gray masses, cystic, focal hemorrhage, minimal mitotic activity and calcification

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16
Q

What is the histology of the cells in an oligodendroglioma?

A

Cells with spherical nuclei containing finely granular chromatin surrounded by a clear halo of vacuolated cytoplasm

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17
Q

What are the characteristics of an anaplastic oligodendroglioma?

A

High cell density, nuclear anaplasia, detectable mitotic activity, and necrosis

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18
Q

What cells and cellular components are in ependymomas?

A
  • Cells with regular, round to oval nuclei and abundant granular chromatin
  • Dense fibrillary background
  • Tumor cells that form rosettes or canals
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19
Q

What are rosettes?

A

Gland-like round structures formed by tumor cells

*Found in ependymomas

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20
Q

What are canals?

A

Elongated structures formed by tumor cells that resemble the embryologic ependymal canal
*Found in ependymomas

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21
Q

When are perivascular pseudorosettes present?

A

When tumor cells are arranged around vessels with an intervening zone of thin ependymal processes directed toward the wall of the vessel

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22
Q

What are the characteristics of an anaplastic ependymoma?

A

Increased cell density, high mitotic rates, areas of necrosis, and less ependymal differentiation

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23
Q

What are myxopapillary ependymomas?

A

Lesions that occur in the filum terminale of spinal cord

24
Q

What are the characteristics of a myxopapillary ependymoma?

A
  • Have cuboidal cells around papillary cores containing connective tissue and blood vessels
  • Contain neutral and acidic mucopolysaccharides
25
Q

What is the difference in location of medulloblastomas in children vs adults?

A

Children: located in the midline of the cerebellum
Adults: lateral locations of the cerebellum

26
Q

What is the appearance of a medullablastoma?

A
  • Well circumscribed, gray, and friable

- Mitoses are abundant and markers of cellular proliferation are in high percentage

27
Q

Microscopic examination of medullablastomas

A
  • Very densely cellular with sheets of anaplastic cells

- Single cells are hyperchromatic nuclei and elongated or crescent shaped

28
Q

What tumors are Homer-Wright rosettes found?

A

Medullablastomas and neuroblastomas

29
Q

What is the nodular desmoplastic variant in medullablastomas?

A
  • Area of stomal response marked by collagen and reticulin deposition
  • Nodules forming “pale islands”
30
Q

What is the large cell variant in medullablastomas?

A
  • Large irregular vesicular nuclei , prominent nucleoli, and frequent mitosis and apoptotic cells
31
Q

What is the term “drop metastases”?

A

When nodular masses form at distance from the primary tumor mainly from CSF dissemination

32
Q

Characteristics of atypical teratoid/rhabdoid tumor

A

Large, soft consistency, that spread along surface of the brain and have lots of mitotic activity

33
Q

What is the appearance of a rhabdoid cell?

A
  • Eosinophilic cytoplasm
  • Sharp cell borders
  • Eccentrically located nuceli
34
Q

Characteristics of Primary CNS lymphoma lesions

A

Lesions are multiple and involve the deep gray matter, white matter, and cortex

35
Q

What is the most common histologic group of primary CNA lymphomas?

A

B-cell lymphomas

36
Q

What is the histologic pattern, “hooping”, and when does it occur?

A

Hooping is when infiltrating cells are separated form one another by silver-staining material
*Seen in primary brain lymphomas

37
Q

What marker is expressed in Primary CNS lymphomas?

A

B cell markers- CD20

38
Q

What is the appearance of a meningioma?

A
  • Rounded mass with well-defined dural bases that compress underlying brain
  • Surface is encapsulated by fibrous tissue
39
Q

What is “en plaque” and when is it seen?

A

When the tumor spreads in a sheetlike fashion along the surface of the dura
*Seen in meningiomas

40
Q

What is the histologic pattern, syncytial, and when is it present?

A

Whorled clusters of cells that sit in tight groups without visible cell membranes
*Seen in meningiomas

41
Q

What is the histologic pattern, fibroblastic, and when is it present?

A

Elongated cells with abundant collagen deposition between them
*Seen in meningiomas

42
Q

What is the histologic pattern, transitional, and when is it present?

A

Share features of syncytial and fibroblastic

*Seen in meningiomas

43
Q

What is the histologic pattern, psammomatous, and when is it present?

A

Psammona bodies that form from calcification of syncytial nests of meningothelial cells
*Seen in meningiomas

44
Q

What is the histologic pattern, secretory, and when is it present?

A

PAS-positive intracytoplasmic droplets and intracellular lumens by electron microscopy
*Seen in meningiomas

45
Q

What is the histologic pattern, microcystic, and when is it present?

A

Loose, spongy appearance and is associated with a specific genotype–> mutations in TRAF7 and KLF4
*Seen in meningiomas

46
Q

What is an atypical meningioma?

A

A lesion with a higher rate of recurrence and more aggressive local growth

47
Q

How are atypical meningiomas distinguished?

A

Have 4 or more mitoses per 10 power fields or at least 3 atypical features

48
Q

What are examples of atypical features?

A

Increased cellularity, small cells with high nuclear-to-cytoplasmic ratio, prominent nucleoli, patternless growth, or necrosis

49
Q

What is an anaplastic (malignant) meningioma?

A

Highly aggressive tumor with the appearance of a high-grade sarcoma but retain histologic evidence of meningioma origin

50
Q

Papillary Meningioma

A

Pleomorphic cells arranged around fibrovascular cores

51
Q

Rhabdoid Meningioma

A

Sheet of tumor cells with hyaline eosinophilic cytoplasm containing intermediate filaments

52
Q

Characteristics of intraparenchymal metastases

A
  • Sharply demarcated
  • At the junction of gray and white matter
  • Surrounded by a zone of edema
53
Q

What metastatic tumor is associated with carcinoma of the lung and breast?

A

Meningeal carinomatosis

54
Q

Characteristics of cortical hamartomas of tuberous sclerosis

A

Firm areas of cortex that are comprised of haphazardly arranged neurons that lack organization

55
Q

What does “candle-guttering” mean and when is it seen?

A
  • Droplike masses that bulge into the ventricular system

* Seen in tuberous sclerosis

56
Q

What are hemangioblastomas?

A

Highly vascular neoplasms that occur as a nodule and are associated with a large fluid-filled cyst

57
Q

What is considered the neoplastic element in hemangioblastomas and why?

A

Stromal cells that express inhibin- they are the neoplastic element because they show the presence of the second “hit” in the preciously normal VHL allele

COM II- Neuro Robbins (8 decks)

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