Neoplasia 1 Flashcards
What is cancer?
A common word for malignant lesions
What is a tumour?
A neoplastic lesion - benign or malignant
What is oncology?
The study of neoplastic lesions
What is neoplasia?
excessive and unregulated cell proliferation
Why does neoplasia occur?
Due to a genetic mutation that affects cell cycle, apoptosis and DNA repair
What are the two types of neoplasia?
Benign and malignant
What are the features of a benign tumour?
Slow growth, well circumscribed, may be encapsulated, well differentiated cells, unable to metastasise, rarely life threatening
What are the features of a malignant tumour?
Invasive and destructive growth locally, poorly circumscribed, frequently induce desmoplasia, may have necrosis, cells are variably differentiated from well differentiated to anaplastic, potential to metastasise
What is desmoplasia?
Where the tumour releases cytokines and growth factors which induce fibroblasts to proliferate and produce extracellular matrix in the stroma which the tumour invades
What are anaplastic cells?
Cells which cannot be determined if they are differentiated
How do tumours metastasise?
Via the lymphatics, via the blood (haematogenous) or along pleural space (transcoelomic)
What are some common sites of metastases?
Liver, brain, lungs, bone - although it is different for different cancers
What feature do metastases from melanoma have?
They are pigmented
How colour are tumours macroscopically?
Pale - often with paler areas within if there is necrosis
What may peritoneal metastases present with clinically?
Abdominal swelling due to fluid production
What is lymphangitis carcinomatosis?
Liv - there was no answer in Evernote
What do neoplastic cells demonstrate histologically?
cytological atypia and architectural disorganisation
What is cytological atypia?
larger nuclei, pleomorphic nuclei, coarse nuclear chromatin, hyper chromatic nuclei, larger more prominent nucleoli, more mitotic activity
What is architectural disorganisation?
Cells are more crowded and less organised
What other features may be seen in neoplasia histologically?
desmoplasia, chronic inflammatory cells, pyknosis and karryolysis
What phenotype do tumour cells usually show?
One that resembles their normal counterparts
What features do tumour cells with glandular cell lineage show?
formation of glandular lumen, signet ring cells, formation of mucin
What features do tumour cells with squamous cell lineage show?
keratinisation (whirls in the middle of the tumour), eosinophilic cytoplasm, intercellular bridges
What features do tumour cells with smooth muscle lineage show?
elongated nuclei with rounded ends, elongated cells
What does the prefix in the name of the tumour mean?
Its cell lineage
What type of tumour is an adeno-?
Glandular
What type of tumour is a leiomyo-?
smooth muscle
What type of tumour is an osteo-?
osteoblastic
What does the suffix in the name of the tumour mean?
Whether it is benign of malignant, and if malignant whether it is mesenchymal or epithelial
What does the suffix -oma mean?
Benign
What does the suffix carcinoma mean?
It is a malignant epithelial tumour
What does the suffix sarcoma mean/
It is a malignant mesenchymal tumour
What are some exceptions to the naming terminology?
seminoma (malignant testicular), lymphoma (malignant lymphocytes)
What is the degree of differentiation?
The extent to which the tumour cells resemble their normal counterparts - differentiation in malignant tumours is referred to as grade
Why is the tumour microenvironment important?
For establishment and growth of metastases
How do genetic alterations which lead to neoplasia arise?
carcinogenic agents (microbes, radiation, chemicals), inherited, mistakes in normal replication, sustained cell proliferation from any cause
What are premalignant lesions?
Cells that are not yet malignant but there is a reasonable chance of them becoming malignant
What else are premalignant lesions called?
dysplasia and intraepithelial neoplasia
How are intraepithelial neoplasias graded?
mild, moderate or severe where severe is an in situ carcinoma
What is an in situ carcinoma?
A severe dysplasia where cells look malignant but haven’t yet invaded past the basement membrane into the stroma
How do dysplasias get past the basement membrane?
With enzymes such as metalloprotinases
What is a polyp?
A glandular dysplastic lesion
