tumour classification and nomenclature

Question 1

what is a tumour/neoplasm

Answer 1

abnormal growing mass of tissues whose growth is uncoordinated with that of surrounding normal tissue and continues after the removal of any stimulus that may have caused the tumour. It is an irreversible change

Question 2

what are the 2 groups of tumours

Answer 2

benign and malignant

Question 3

what is a benign tuour

Answer 3

doesnt cause significant pathological or clinical problems

Question 4

what is a malignant tumour

Answer 4

cancerous
A fundamental property of cancer (or malignant tumour) is its ability to invade into adjacent tissue and to metastasise (spread) and grow at other sites within the body and are known as 2y tumours and make treatment much more difficult

Question 5

classification of tumours

Answer 5

• Important for understanding tumour behaviour and determining outcome (prognosis) and selecting therapy
• Based on tissue of origin (epithelium, connective tissue, blood cells, lymphoid tissue, melanocytes, neural tissue , germ cells)
• Benign vs malignant

Question 6

benign tumour on epithelial tissue

Answer 6

adnoma

Question 7

malignant tumour on glandular tissue

Answer 7

adeno-carcinoma

Question 8

benign tumour on squamous tissue

Answer 8

squamous papilloma

Question 9

malignant tumour on squamous tissue

Answer 9

squamous carcinoma

Question 10

benign tumour on bone

Answer 10

osteoma

Question 11

malignant tumour on bone

Answer 11

osteosarcome

Question 12

benign tumour on fat

Answer 12

lipoma

Question 13

malignant tumour on fat

Answer 13

lipo-sarcoma

Question 14

benign tumour on fibrous tissue

Answer 14

fibroma

Question 15

malignant tumour on fibrous tissue

Answer 15

fibrosarcoma

Question 16

what is a sarcoma

Answer 16

malignant connective tissue tumour

Question 17

malignant tumour of white blood cells

Answer 17

leukaemia

Question 18

malignant tumour of lymphoid tissue

Answer 18

lymphoma

Question 19

benign tumour of melanocyte

Answer 19

naevus

Question 20

malignant tumour of melanocyte

Answer 20

melanoma

Question 21

nomenclature of tumours of neural tissue

Answer 21

• CNS: Don’t necessarily behave in the same way as tumours elsewhere due to the confined space and volume, astrocytoma (supporting cells of CNS)
  PNS: schwannoma

Question 22

nomenclature of germ cell tumours

Answer 22

• Teratomas
  
  • Tumour composed of various tissues
  • Develop in ovary/testis
  • Ovarian teratomas usually benign, testicular teratomas usually malignant

Question 23

what do we look for in the features of tumours

Answer 23

Growth pattern - (invasive growth pattern when malignant)
Invasion - Presence of metastases
Differentiation - Appearance of tumour cells (does it look similar to the normal tissue)
Function - behaviour
(is its function like that of the normal tissue)

Question 24

features of benign tumours

Answer 24

non-invasive growth pattern 
no evidence of invasion
cells similar to normal and function similar to normal tissue
benign tumours are well - differentiated
rarely cause death
usually encapsulated
no metastases

Question 25

features of malignant tumours

Answer 25

• Invasive growth pattern - combination of spread and destruction
  
  • No capsule or capsule breached by tumour cells
  • Cells abnormal
  • Cancers often ‘poorly differentiated’ - don’t look similar to normal tissue
  • Loss of normal function
  • Often evidence of spread of cancer - e.g. in nearby lymph nodes
    Frequently cause death