Neoplastic and non-Neoplastic disorders of cell growth

What is hypertrophy?

increase in size of a cell/tissue without cell division

Give 2 examples of physiological hypertrophy:

skeletal muscle that occurs with training in athletes

Myometrium of uterus during pregnancy

give an example of pathological hypertrophy:

cardiac muscle of the LV due to outflow obstruction eg aortic stenosis or increased after load eg systemic hypertension

What is hyperplasia?

increase in number of cells in a tissue as a consequence of cell division (no cell size increase)

example of physiological hyperplasia:

adaptive increase in erythrocyte production leading to increased number of red cells in individuals at high altitude

Low PO2 leads to increased EPO production that stimulates bone marrow erythropoiesis. -erythroid hyperplasia

What is atrophy?

decrease in size of an organ/cell, can be result of reduction in cell size/number

May be mediated by reduced cell proliferation or increased cell loss due to increased apoptosis

give examples of atrophy:

disuse (decreased workload)

Loss of innervation

Diminished blood supply

Inadequate nutrition

Loss of endocrine stimulation

Ageing (sense atrophy)

Pressure

what cellular response leads to Alzheimer’s?

Brain ATROPHY

What is metaplasia?

replacement of one type of mature differentiated cell type with another mature differentiated cell type as an adaptive response to some insult or injury

what is an example of pathological hyperplasia?

psoriasis - characterized by excessive proliferation and abnormal differentiation o karatinocytes and infiltration of inflammatory cells

squamous metaplasia

toxic effects of tobacco smoke

Lead to airway epitheial injury

Reversible replacement of normal pseudostratified columnar epithelium by squamous epithelium

what is Barrett’s oesophagus?

Squamous epithelium lining oesophagus is replaced by tissue similar to intestinal lining

Intestinal metaplasia

Increased risk of adenocarcinoma

what is dysplasia?

reversible condition where epithelial cells acquire some but not all of the features and properties of malignant cells

But without capacity for invasion

neoplasm

an abnormal mass of tissue (tumour)

Growth of which is uncoordinated with that of normal tissue

Persists in the same excessive manner after cessation of the stimulus which evoked the change

which type of tumour holds the following behaviours:

Slow growing

Never invades local tissues

Never metastasises (spread)

benign

which type of tumour holds the following behaviours:

Variable and may be radid growing

May invade surrounding tissues

May metastasise

malignant

which type of tumour holds the following characteristics:

Usually well circumscribed or encapsulated

benign

which type of tumour holds the following characteristics:

Poorly defined or irregular

malignant

what is the link between neoplasms and cancer?

cancer is malignant neoplasm

But not all neoplasms are cancer

which type of tumour holds the following characteristics:

Few mitoses

Usually resemble tissue of origin

Necrosis rare

Nuclear morphology normal

benign

which type of tumour holds the following characteristics:

May be mitoses

May only poorly resemble tissue of origin

Necrosis common

Nuclear morphology variable

malignant

Carcinoma

malignant tumour of epithelial origin

sarcoma

malignant tumour of connective tissue (mesenchmye) origin

adenoma

benign tumour of glands

adenocarcinoma

malignant tumour of glands

adeno-

glandular epithelium

papillo-

non-glandular epithelium

lipo-

fat

osteo-

bone

chondro-

cartilage

angio-

blood vessel

rhabdo-

skeletal muscle

leiomyo-

smooth muscle

What does the grade of a tumour refer to?

degree of differentiation of a tumour

Degree to which it resembles its presumed normal counterpart

What is macroscopic invasion?

where cancers invade surrounding structures

what is microscopic invasion?

where cancers digest through the basement membrane to invade parenchymal cells

what is metastasis?

the process of discontinuous spread

what are the 3 routes of metastasis?

direct seeding of body cavities

Lymphatic spread

Hematogenous spread

which body cavity is most commonly seeded by cancers?

peritoneal

what is the most common pathway for initial dissemination of carcinomas/melanomas?

lymphatic spread

which tumours do not normally spread to lymph nodes?

sarcomas

hematogenous spread is typical of what type of cancer?

sarcomas

But also carcinomas

which organs are most frequently involved with hematogenous spread?

liver

Lungs