Mesenchymal Neoplasms Flashcards

1
Q

What are the characteristics of mesenchymal cells?

A

variable exfoliation

indistinct, wispy cytoplasmic borders

spindle shaped, fusiform, stellate cells

cell individually arranged

more oval shaped nuclei than epithelial cells

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2
Q

Tissue of origin?

Benign or malignant?

Tumor type?

A

mesenchymal

malignant

Leiomyosarcoma

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3
Q

Which mesenchymal tumors may need histopathology to determine biological behavior?

A

Muscle tumors= Leiomyoma/sarcoma & myxoma/sarcoma

Cartilagenous tumors= chondroma/sarcoma

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4
Q

Via which route do mesenchymal tumors typically metastasize?

A

hematogenous routes

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5
Q

Describe the characteristics of malignancy in this sample? What general classification would this tumor be?

A

Anisokaryosis, mitotic figures, open chromatin, multiple nucleoli

Sarcoma

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6
Q

Tumor type?

Benign or malignant?

A

mesenchymal- lipoma

benign

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7
Q

An owner reports that she thinks a previously diagnosed lipoma has become cancerous and spread to the other areas of the dog’s ventrum. Is this a possibility?

A

No, liposarcomas do not arise from malignant transformations of lipomas

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8
Q

If you suspect that around an surgery scar there is an area of scar tissue/reactive fibroplasia, what should you do to confirm?

A

Histopathology

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9
Q

What is the most common cutaneous tumor of horses?

A

sarcoid

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10
Q

A firm, SQ mass is palpated on the hind end of a horse. On cytology of the mass, it appears mesenchymal. What are the top three differentials? How would you confirm?

A

sarcoid

Granulation tissue

fibroma

Perform histopathology to confirm tumor and biologic behavior

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11
Q

What four ST sarcomas do we typically all treat the same?

A

perivascular wall tumor

fibrosarcoma

myxosarcoma

peripheral nerve sheath tumor

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12
Q

Describe the characteristics of perivascular wall tumors.

A

High exfoliation

very vascular

multinucleated cells with peripheral nuclei (crown cells)***

very wispy cytoplasm and anaplastic cells

small punctate vacuoles

1-2 nucleoli

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13
Q

Tumor type?

A

mesenchymal, perivascular wall tumor

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14
Q

Tumor type

A

Soft tissue sarcoma

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15
Q

Tumor type?

A

ST sarcoma

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16
Q

Where are perivascular wall tumors commonly found?

A

on the extremities, especially the lateral surface

17
Q

When is a biopsy for a mass from a vaccination warranted?

A

present 3 months after vaccination

>2 cm in diameter

increasing in size 1 month after vaccination

18
Q

What are the characteristics of fibrosarcomas?

A

low exfoliation

individual arranged cells

pink eosinophilic matrix (collagen)

absence of inflammation

19
Q

What comparative measure can be used to determine if a nucleus is enlarged?

A

compare to the size of a RBC

20
Q

T/F Fibrosarcomas metastasize quickly.

A

FALSE

21
Q

What are the characteristics of hemangiosarcomas on cytology? In which sites do we typically see these tumors?

A

variable exfoliation (hemodilute often)

large, typical cells

pale blue cytoplasm with clear vacuoles

Sites: spleen, liver, R-atrium, retroperitoneal space, bone, dermal (derived from mets most often)

22
Q

Tumor type?

Benign or malignant?

A

Mesenchymal, hemangiosarcoma

[pale blue cytoplasm, cytoplasmic vacoules]

malignant

23
Q

What are the site predilections for synovial cell sarcomas?

A

elbow, stifle, shoulder

24
Q

Which tumor is hard to differentiate from synovial cell sarcoma on histo and cyto? (special stains needed)

A

Histiocytic sarcoma

25
Q

synovial cell sarcomas are locally invasive and metastasize in 25% of reported cases. T/F

A

True

26
Q

What are the features of synovial cell sarcomas?

A

granular eosinophilic background (mucin)

Dual population of anaplastic cells:

  1. oval with eccentrically placed nuclei
  2. spindle shaped
27
Q

Name the three types of tumors that can affect the joints? What are their site/breed predilections?

A
  1. Synovial cell sarcoma- elbow, stifle, shoulder
  2. Histiocytic sarcoma- stifle, Rottweiler
  3. Synovial myxoma-stifle, Doberman
28
Q

Tumor type?

A

Synovial cell tumor

(eosinophilic background, two aplastic cell populations)

29
Q

What are the characteristics of osteosarcomas?

A

May appear as round cell tumors

Eccentric nuclei

Large, oval - spindle shaped cells (individual)

Dense, amorphous pink material (osteoid***)

variable, distinct cytoplasmic borders

muti-nucleated giant cells (osteoclasts)

30
Q

What is the most common site for osteosarcoma in the cat?

A

femur

31
Q

What are the sites common for osteosarcoma in a dog?

A

metaphyseal region

“away from the elbow, towards the knee”

  • proximal humerus
  • distal radius & ulna
  • proximal tibia
  • distal femur
32
Q

Tumor type?

A

Osteosarcoma

(osteoid in the cells pink granular material is the give away)

33
Q

Does osteosarcoma have a better prognosis in the cat or dog? Axial or appendicular skeleton?

A

cat

axial skeleton

34
Q

What is the first diagnostic that should be performed on a dog with suspected osteosarcoma on the appendicular skeleton?

A

thoracic radiographs

35
Q
A