Cellular pathology of cancer

Question 1

what is metaplasia?

Answer 1

A reversible change in which one (adult) cell type (usually epithelial) is replaced by another (adult) cell type.

An adaptive change e.g in response to regurgitated stomach acid (Barrett’s oesophagus)

Question 2

what are the two types of metaplasia? what are the differences?

Answer 2

1) gastric metaplasia (columnar epithelium & NO goblet cells)
2) intestinal metaplasia (columnar epithelium & goblet cells)

Question 3

what is dysplasia?

Answer 3

An abnormal pattern of growth in which cellular and architectural features of malignancy are present.

Question 4

what are the pre-invasive changes in dysplasia?

Answer 4

intact basement membrane, cannot spread

Loss of architecture and loss of uniformity of individual cells.

Question 5

what are the feature of dysplasia?

Answer 5

Nuclei = hyperchromic, enlarged.

Mitotic figures (condensed DNA material) = abundant, abnormal (in places not normally found)

Question 6

which locations are dysplasia common?

Answer 6

• Cervix (HPV)
• bronchus (smoking)
• colon (UC)
• larynx (smoking)
• stomach (pernicious anaemia)
• oesophagus (acid reflux)

Question 7

what are the two descriptors of dysplasia?

Answer 7

High grade (darker nuclei) or low grade.

Question 8

what is neoplasia?

Answer 8

An abnormal, autonomous proliferation of cells unresponsive to normal growth control mechanisms.

tumour/malignancy

Question 9

what are the characteristics of neoplasia?

Answer 9

 Do not invade, do not metastasize.

 Encapsulated (not always)– i.e. Leiomyomas are NOT encapsulated but ARE benign.

 Usually well-differentiated.

 Slow-growing.

 Normal mitotic figures.

Question 10

neoplasms are usually not fatal unless…?

Answer 10

 Dangerous place – I.e. pituitary.
 Secretes dangerous chemicals – I.e. insulinoma.
 Gets infected – I.e. bladder infection from obstruction of ureter.
 Bleeds – i.e. stomach tumours.
 Ruptures – i.e. liver adenoma.
 Torts – i.e. ovarian cyst (twists and cuts off own blood supply).

Question 11

what are the characteristics of malignant tumours?

Answer 11

	Invade surrounding tissue.
	Metastasize.
	No capsule (but not always).
	Well to poorly differentiated (but tend to be poorly differentiated).
	Rapidly growing.
	Abnormal mitotic figures.

Question 12

what is a metastasis?

Answer 12

discontinuous growing colony of tumour cells, at some distance from the primary.

Question 13

what does metastasis depend on?

Answer 13

local blood and lymphatic supply

Lymph node involvement has a worse prognosis (e.g. Dukes A is a confined colon cancer with 90% cure rate as opposed to Dukes B which metastasises)

Question 14

the two types of benign epithelial tumours?

Answer 14

o Surface epithelium = Papilloma – e.g. skin.

o Glandular epithelium = Adenoma – e.g. thyroid cancer.

Question 15

what is a carcinoma?

Answer 15

malignant tumour derived from epithelium

Question 16

what are the types of carcinoma?

Answer 16

• Squamous cell carcinoma – squamous cell malignancy.
• Adenocarcinoma – glandular epithelium malignancy.
• Transitional cell carcinoma – transitional cells line the urinary tract.
• Basal cell carcinoma – arise from the skin.

Question 17

example of benign soft tissue tumours

Answer 17

osteomas

Question 18

what is a sarcoma?

Answer 18

malignant tumour derived from connective tissue (mesenchymal) cells

Question 19

what are the types of sarcoma?

Answer 19

• Liposarcoma (fat derived), osteosarcoma, chondrosarcoma (cartilage).
• Rhabdomyosarcoma – striated muscle tumour.
• Leiomyosarcoma – smooth muscle tumour.
• Malignant Peripheral Nerve Sheath Tumour – nerve sheath tumour.

Question 20

what are leukaemia and lymphomas?

Answer 20

tumours of white blood cells

o Leukaemia’s – malignancy of bone-marrow-derived cells in the peripheral blood.

o Lymphomas – malignancy of lymphocytes (usually) in the lymph nodes.

Question 21

what is a teratoma?

Answer 21

tumour derived from germ/stem cells which has the potential to develop into all three germ cell layers
(ectoderm, mesoderm and endoderm)

e.g. Dermoid cysts – can contain anything such as teeth, bone, eyes, etc

Question 22

what are gonadal teratomas?

Answer 22

Males – all malignant, Females – most are benign.

Question 23

what are hamartomas?

Answer 23

localised overgrowth of cells/tissue native to the organ – e.g. Bile duct hamartoma

Question 24

what are the features of hamartomas?

Answer 24

Cells are mature but architecturally abnormal

• You find the same types of tissue expected to grow in the organ but not in the right place in the organ.
• Common in children but often stop growing when the child stops growing

Question 25

what is the criteria for assessing level of differentiation of a malignant tumour?

Answer 25

1. Evidence of normal function is still present – i.e. production of keratin, mucin 2. If no evidence of normal function – high-grade or anaplastic carcinoma 3. If no evidence of differentiation – anaplastic carcinoma 4. Presence of abnormal mitoses, the higher the worse it behaves (mitotic count) 5. various grading system for cancer of the breast, prostate and colon etc

Question 26

TNM

Answer 26

 Grade – describes degree of differentiation.  Stage – describes how far it has spread. applied to tumours at all sites

Question 27

what is the more clinically significant factor in TNM?

Answer 27

Stage is MORE important than grades (for prognosis determining higher grade tends to mean higher stage