Tumour Classification Flashcards
What suffix do most tumours share?
Which characteristics determine how they are named?
most have the suffix “oma”
they are classified by histological origin, whether they are benign or malignant and whether they are primary or secondary
Why is naming tumours important?
- it characterises the lesion’s behaviour
- it determines prognosis
- it outlines treatment options
What are the 2 basic tissue types involved in histological classification?
epithelium:
this is tissue that lines surfaces
mesenchymal tissue:
- connective tissue (bones, ligaments, tendons, fat, cartilage)
- muscle
- nervous tissue
- marrow (haematological malignancies arise from different components that make up the blood cells)
What are the 2 types of benign epithelial tumours?
papillomas or adenomas
this depends on whether the epithelium is either glandular/secretory or not
What is an adenoma?
a benign epithelial tumour of glandular/secretory epithelium
What is a papilloma?
a benign epithelial tumour or non-secretory/non-glandular epithelium
How are papillomas classifed further?
by the cell type of origin
e.g. squamous cell papilloma, urothelial cell papilloma
How are adenomas further classified?
by the glandular tissue of origin
e.g. colonic adenoma, thyroid adenoma
What is the name for a malignant epithelial tumour?
carcinoma
What is an adenocarcinoma?
a malignant epithelial tumour of glandular epithelium
they can arise from any glandular epithelium, but the organ needs to be specified
e.g. lung adenocarcinoma, colorectal adenocarcinoma
How are carcinomas of non-glandular epithelium named?
based on the cell type that they have originated from
e.g. basal cell carcinoma, urothelial cell carcinoma
What is meant by a carcinoma “in-situ”?
the carcinoma has not yet invaded through the basement membrane
invasion is preceded by dysplasia (disordered maturation and nuclear changes)
if no action is taken, the carcinoma will invade
What are the following prefixes for benign mesencymal tumours?
the suffix is “oma”
e.g. tumour of bone would be osteoma
What are the prefixes and suffix for malignant mesenchymal tumours?
the suffix is ‘sarcoma’
e.g. a malignant tumour of adipose tissue would be liposarcoma
What are leiomyomas more commonly known as?
fibroids in the uterus
they are benign tumours of smooth muscle
What is the proper name for a mole?
melanocytic naevus
it is a benign melanocytic lesion that has many sub-types
What is a malignant melanoma?
it can be in-situ or invasive
it looks like a mole but is darker in colour and has a varying texture
What is a mesothelioma?
a tumour of the pleura covering the lungs
it is always invasive (no benign counterpart) and nearly always fatal
What are the 3 main types of CNS tumours?
- tumours of the meninges (lining of the brain) - meningioma
- tumours of glial cells - glioma
- ptiuitary tumours
How do neurones in the CNS form tumours?
neurones in the CNS rarely form tumours
tumours in the brain form from the glial cells (supportive cells)
In the PNS, neurones can form tumours
How often do tumours metastasize to the brain?
may tumours metastasize to the brain but generally not vice versa
this is due to the blood-brain barrier
Where are germ cells found?
germ cells make up the gonads (ovary and testis)
they are also found in the midline as primordial germ cells originate in the midline and then migrate to the gonads
What are the 2 main types of germ cell tumours?
seminoma - originates from sperm cells in the testes
dysgerminoma - originates from oocytes
