Using The Pathologist

Question 1

Define Neoplasia 
(Three key points)

Answer 1

An uncontrollable proliferation of cells

Proliferation continues in the absence of inciting cause

Neoplastic cells originate from a single cell which has undergone mutation and lost the ability to control its division

Question 2

Which patients are particularly prone to developing squamous cell carcinomas?

Why?

Where are they usually found?

Answer 2

White cats

Lack melanin in the skin

Nasal planum and ear tips

Question 3

How do benign tumours grow?

Answer 3

Expansion

Question 4

Describe the growth rate of benign tumours

Answer 4

Low to moderate

Question 5

Describe the gross appearance of a benign tumour in relation to the surrounding tissue

Answer 5

Well-demarcated from surrounding tissue

Smooth outline

Question 6

What usually surrounds a benign tumour?

Answer 6

Connective tissue capsule

Question 7

How do benign tumours usually feel on palpation?

Answer 7

Freely movable

Question 8

Describe the cut surface of a benign tumour

Answer 8

Homogeneous

May be cystic in glandular tissues

(Generally little haemorrhage or necrosis)

Question 9

How easy/successful is surgical removal of benign tumours?

Answer 9

Often easy (dependent on location)

No recurrence if completely excised

Question 10

What is a key feature of benign tumours?

Answer 10

No metastasis to elsewhere in the body

Question 11

Describe the microscopic features of benign tumours

Answer 11

Often very similar to the tissue of origin

Tissue well organised

Endocrine tumours can be functional

Surrounding connective tissue capsule that tumour doesn’t broach

Few/no mitoses

Generally no haemorrhage or necrosis

Question 12

Describe the growth of malignant tumours

Answer 12

Growth by invasion into adjacent tissue

Question 13

Are malignant tumours usually encapsulated?

Answer 13

No

Question 14

Describe how malignant tumours feel on palpation

Describe their usual gross appearance if on skin/mucosa

Answer 14

Usually not mobile

Often ulcerate if on skin or mucosal surface

Question 15

How easy/successful are surgical attempts to remove malignant tumours?

Answer 15

Complete removal often difficult

Often recurs after excision

Question 16

Describe the internal appearance of a malignant tumour

Answer 16

Frequently show internal necrosis or haemorrhage

Question 17

Can malignant tumours metastasise?

If so, where?

Answer 17

Yes - some more readily than others

First to local lymph nodes, lungs

Question 18

Describe the microscopic features of malignant tumours.

Answer 18

—Variable cell size and shape - anisocytosis / pleomorphism
— Anisokaryosis
—increased nuclear:cytoplasm
—prominent nucleoli
— presence of mitoses
— loss of cohesiveness and structure
— malignant fusion -> multinucleated cells
— secondary changes -> necrosis, fibrosis, inflammation
— usually unencapsulated - if presence, often invaded

Question 19

What do you term a benign tumour of the surface epithelia (e.g. skin)?

Answer 19

Papilloma

Question 20

What do you term a benign tumour of the glandular epithelia?

Answer 20

Adenoma

Question 21

What is used as a prefix for benign tumours of epithelial origin?

Answer 21

Tissue of origin e.g. squamous, thyroid

Question 22

What do you term a malignant tumour of epithelial origin?

Answer 22

Carcinoma

Question 23

What do you term a malignant tumour of the glandular epithelium?

Answer 23

Adenocarcinoma

Question 24

Where is the tissue of origin stated for malignant tumours of epithelial origin?

Answer 24

Added at the beginning e.g. squamous cell carcinoma, mammary adenocarcinoma

Question 25

What is the basic rule when naming malignant and benign tumours of mesenchymal origin?

Answer 25

Benign - add -Oma to the tissue of origin Malignant - add -sarcoma to the tissue of origin

Question 26

Give the names for benign and malignant tumours of fibrous tissue origin

Answer 26

Fibroma Fibrosarcoma

Question 27

Give the names for benign and malignant tumours of bone tissue origin

Answer 27

Osteoma Osteosarcoma

Question 28

Give the names for benign and malignant tumours of cartilage tissue origin

Answer 28

Chondroma | Chondrosarcoma

Question 29

Give the names for benign and malignant tumours of adipose tissue origin

Answer 29

Lipoma Liposarcoma

Question 30

Give the names for benign and malignant tumours of smooth muscle tissue origin

Answer 30

Leiomyoma | Leiomyosarcoma

Question 31

Give the names for benign and malignant tumours of endothelial tissue origin

Answer 31

Haemangioma Haemangiosarcoma

Question 32

Give the names for benign and malignant tumours of skeletal muscle tissue origin

Answer 32

Rhabdomyoma | Rhabdomyosarcoma

Question 33

What is a granuloma?

Answer 33

NOT a neoplasm Organised type of chronic inflammation

Question 34

What is a lymphoma? Are they usually benign or malignant?

Answer 34

Tumours of the lymphoid system Usually malignant

Question 35

What is a Melanoma ? Are they usually benign or malignant?

Answer 35

Tumour of melanocytes Some benign others malignant (‘Malignant melanoma ‘).

Question 36

What is a mast cell tumour? Are they usually benign or malignant?

Answer 36

Tumour of mast cells (mastocytoma) Vary in degrees of malignancy

Question 37

What is leukaemia? Are they usually benign or malignant?

Answer 37

Tumours derived from cells of the bone marrow which circulate in the blood

Question 38

What is a teratoma? Are they usually benign or malignant?

Answer 38

Germ cell tumours with elements of ectoderm, endoderm and mesoderm

Question 39

What are sarcoids? What causes them?

Answer 39

Low grade fibrosarcoma commonly seen in the skin of horses BPV

Question 40

What are the four routes of tumour metastasis?

Answer 40

Lymphatic Vascular Trans-coelomic Local

Question 41

What tumours commonly use lymphatic spread for metastasis? What do you expect to find in lymph nodes?

Answer 41

Carcinomas Draining lymph nodes contain secondary metastases

Question 42

Which tumour type tends to favour vascular metastasis? Where would you expect to find secondary tumours?

Answer 42

Sarcoma Seeds widely to internal organs e.g. liver and lungs

Question 43

Which tumour type tends to favour trans-coelomic metastasis? Where do you find secondary tumours?

Answer 43

Mesothelioma or ovarian carcinoma Tumour spreads across serosal surfaces (may be associated with effusion)

Question 44

Where would you expect to find secondary tumours when local metastasis occurs?

Answer 44

Spread along fascial planes

Question 45

What are multicentric tumours?

Answer 45

Multiple tumours present on first presentation | — difficult to determine a primary site as multiple tumours present at first presentation