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Oncology > Using the Pathologist > Flashcards

Flashcards in Using the Pathologist Deck (28)
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1
Q

What are the key features to distinguish neoplasia?

A

-

2
Q

Define neoplasia

A
  • uncontrolled proliferation of cells- proliferation continues in abscence of inciting cause neoplastic cells originate from a single cell (has undergone mutation and lost the ability to control its division)
3
Q

Define hyperplasia

A

Proliferation of cells that stops when inciting cause is removed

4
Q

What does current research show neoplastic cells may be ?

A

2 types of cells not just monoclonal

5
Q

How do benign tumours grow? How do they appear clinically and pathology?

A
  • slowly by expansion- well demarkated from surrounding tissue (may be compressed)- surrounding tissue capsule- freely mobile on palpation- uniform cut surface (may contain cysts) - little hamorrghage or necrosis
6
Q

What is a haemangioma?

A

benign tumour of the blood vessel wall endothelium

7
Q

Microscopic features of benign tumours?

A
  • cells similar to tissue of origin- well organsied - share the functional purpose of tissue- contained in capsule- cells not mitotically active - little evidence of 2* change (haemorrhage or necrossi)
8
Q

Characteristics of malignant tumours

A
  • grow by invasion- not encapsulated- not mobile on palpation - complete removal difficult- often ulcerate if on skin or mucosa- recurs after removal- surface necrosis and naemorrhage- METASTASIS
9
Q

Which breed are predisposed to hamemangiosarcoma?

A

GSD

10
Q

Microscopic feeatures of malignancy?

A
  • pleioporphism (different looking cells)- anisokaryosis (differnet sized nuceli?)- ^ nucleus:cytoplasm ratio- normal/abnormal mitoses- loss of cohesiveness and structure- malignat fusion -> syncitia- 2* changes (necrosis inflamm etc.)- not encapsulated/extending beyond the capsule
11
Q

Name some benign tumours of epithelial origin

A

> surface or non-glandular epithelia = papilloma> glandular epithelia = adenoma

12
Q

Name the main types malignant tumours of epithelial origin

A

> epithalial = carcinoma> glandular epithelia = adenocarcinoma

13
Q

What is the suffix for mesenchymal origins?

A
  • benign = -oma- malignant = -sarcoma
14
Q

What is the exception to the -oma tumour rule?

A
  • Granuloma - not a tumour! Just chronic inflammation
15
Q

What are lymphomas?

A
  • tumouro fthe lymphoid system = MALIGNANT!
16
Q

What are melanomas?

A

Benign OR malignant tumour or melanocytes

17
Q

What are mastocytomas?

A

Can be benign or malignant mast cell tumours

18
Q

What are leukaemias?

A

tumours derived from cells of bone marrow, circulate in the blood

19
Q

What are sarcoids?

A

low grade fibrosarcomas commonly seen in horses (bovine papillomavirus infection)

20
Q

What are the 4 routes of metastasis? Which tumours spread this way?

A

> lymphatic- carcinoma- LNs draining tumour contain 2* deposits > vascular - sarcoma- tumour seeds widely to internal organs (liver and lungs, multiple 2*) >trans-cavity- mesothelioma or ovarian neoplasia- spread acorss serosial surfaces eg. effusion > local - multiple tumour types - spread along fascial planes

21
Q

WHat are multicentric tumours?

A

eg. lymphoma- difficult to determine primary site

22
Q

Which malignant tumours are most likely to metastasise rapidly and constantly?

A
  • tonsillar carcinomas- pancreatic carcinomas- osteosarcomas- oral and digital melanomas- mammary carcinomas (cats)
23
Q

Which malignant tumours metastasise slowly or rarely?

A
  • squamous cell carcinomas- fibrosarcomas > invade locally, recurr but not liekly to metastasise
24
Q

How may immunohistochemistry be used to dx tumour?

A
  • poorly differentiated tumours cannto be IDed on morphological grounds alone- cell surface markers eg. cytokeratin, B/T cell lymphomas
25
Q

Which lymphoma has better prognosis?

A

B cell (T cell responds less well to chemotherapy)

26
Q

What is tumour grading?

A

Carried out by pathologist- high grade = poor prognoses and vice versa

27
Q

Methods of tumuour grading?

A

> light microscopy (SCC)- how closely does it resemble the parnent tissue? low grade = keratin pearls due to excessive keratin production. high grade cannot see keratin so much. > Immunophenotyping (lymphoma) - less CD3 (weaker staining) = HIGH GRADE > detecting genetic mutations (lymphoma) - standard practice in human medicine - tailor tx to individual tumours > proliferation markers (MCT)- eg. Ki-67 (showing mitosis levels) score

28
Q

How should a “representative sample” be obtained to send to the pathologist?

A

> inicsional- include margin normal tissue- avoid necrotic and cavitated areas (EXCEPT for bone tumours where sample of maximal bone lysis is helpful) - mark margins of interest- ID smaples from different sites- include imagine data - fix properly (neutral buffered formalin at least 4:1 ratio)- smaller that 2cm sample- dont hurt mailman