neoplastic disease of the GI tract revision W8

Question 1

what is hyperplasia

Answer 1

tissue growth due to an increase in cell number (not increase in cell size - hypertrophy)
can be physiological or pathological

Question 2

what is metaplasia

Answer 2

change from one fully differentiated cell type to another fully differentiated cell type

Question 3

what is neoplasia

Answer 3

the development of a neoplasm, ie an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue, and which persists even after the evoking stimulus (if known) is removed.

Question 4

what is dysplasia

Answer 4

descriptive term used by pathologists to indicate a pattern of disordered growth and differentiation, typically applied to epithelial tissue.

doesn’t describe a pathological process, rather an appearance seen down the microscope.

Question 5

dysplasia and neoplasia?

Answer 5

cells showing dysplasia may already be neoplastic, or show pre-neoplastic changes, however dysplastic changes can revert back to normal in some cases

Question 6

dysplasia classifications?

Answer 6

low grade and high grade - based on the extent by which the growth pattern deviates from that of normal tissue.

Question 7

what is severe dysplasia often referred to in epithelial tissue?

Answer 7

carcinoma in situ (also known as intraepithelial neoplasia)

Question 8

dysplasia key features?

Answer 8

hyperchromatism (increased staining of nuclei reflecting increase in DNA content)

nuclear pleomorphism (variation in nuclear shape/size)

loss of orientation (loss of polarity)

cell crowding and stratification (loss of normal contact inhibition)

increased/abnormal mitotic figures (increased cell proliferation)

Question 9

how are cancers named?

Answer 9

malignant neoplasm in :

epithelial tissue -> carcinoma
soft tissue -> sarcoma
haematological -> lymphoma/leukaemia

Question 10

common types of carcinoma?

Answer 10

adenocarcinoma = tumours showing glandular (columnar) cell differentiation

squamous cell carcinoma

Question 11

common types of sarcoma?

Answer 11

osteosarcoma (bone)
chondrosarcoma (cartilage)
leiomyosarcoma (smooth muscle)

Question 12

what causes neoplasia

Answer 12

chemical carcinogens
physical agents
infections
inherited susceptibility
hormonal stimulation

Question 13

mechanisms of neoplasia?

Answer 13

direct/indirect damage to DNA
reduced ability to repair DNA damage
increased stimuli to proliferate
reduced ability to inhibit growth
defects in apoptosis

Question 14

benign neoplasm features?

Answer 14

well differentiated
slow growing
normal mitotic figures
no local invasion!!!!
no metastasis!!!!

Question 15

malignant neoplasm features?

Answer 15

lack of differentiation
erratic/rapid growth
may be abnormal mitotic figures
local invasion!!!!
metastasis!!!!

Question 16

routes of metastasis?

Answer 16

lymphatic (common)
vascular (normally veins)
perineural and intraneural
spread across cavities
iatrogenic

Question 17

effects of benign tumours?

Answer 17

bleeding - erosion and ulceration
space occupying lesions within skull
compression of adjacent structures
obstruction of lumina (eg intrassusception in GI tract
hormonal effects (increased/decreased production)

Question 18

what is intrassuception?

Answer 18

polyp propelled forward by waves of peristalsis, causing the bowel to “telescope”. this causes obstruction of the lumen and compresses the venous drainage, leading to ischaemia.

Question 19

2 categories of ‘borderline’ tumours?

Answer 19

tumors that show extensive local invasion, but almost never metastasise (prone to local recurrence if incompletely excised)

tumours that appear entirely benign at time of diagnosis, but then develop distal metastatic disease (often late after diagnosis).

Question 20

grading of malignant neoplasms?

Answer 20

an attempt to predict the aggressiveness of a cancer based on its microscopic features.
high grade cancers are typically poorly differentiated, worse prognosis.
low grade cancers are well differentiated, better prognosis.

Question 21

most important prognostic feature of cancer?

Answer 21

staging (based on TNM classification)