1 Tumour Definition and Nomenclature Flashcards
Define hyperplasia
increase in number of normal cells
give causes for hormonal hyperplasia + state what effect it has on risk of cancer
- increased hormonal stimulation - increase risk in cancer (e.g. endometrial gland hyperplasia due to increase in oestrogen)
- increase in sensitivity to hormone - no effect on cancer risk (e.g. Benign prostatic hyperplasia (BPH), which is caused by an increase in sensitivity to dihydrotestosterone (DHT))
give causes for chronic irritation hyperplasia
- constant scratching of itchy skin, producing thickening (hyperplasia of epidermis)
- bronchial mucus gland hyperplasia, commonly occurs in smokers and asthmatics
state other causes of hyperplasia
- chemical imbalance (e.g. iodine deficiency = thyroid enlargement as gland has to work harder to increase thyroid hormone synthesis)
- stimulating antibody (hyperthyroidism in Grave’s disease; due to thyroid-stimulating antibodies (IgG) directing against thyroid hormone receptors)
- viral infection (e.g. skin infections by HPV produces epidermal hyperplasia - common wart)
Define neoplasia
new overgrowth of abnormal tissue not under normal physiological control (both benign or malignant tumours)
Define benign tumours
benign tumours are usually well differentiated, even though they are a neoplasm they resemble their parent tissue and have no metastatic potential
Define malignant tumour
Tumour involving a neoplasm, which can lead to cancer (can include blood cancer)
How to grade a malignant cancer + list the grades
Whether tissue resembles parent tissue
- Is it well differentiated (low-grade) - parent tissue
- poorly differentiated, high grade or anaplastic does not resemble parent tissue
- intermediate grade; features are between a low and high grade cancer (occasional gland-like structures are seen)
define anaplasia
the loss of mature or specialised features of a cell/tissue - malignant tumours
State the main types of benign tumour + where they originate form
(they end in -oma)
Epithelial, connective tissue (Mesenchymal)
- they can arise originate from ectoderm (squamous) or endoderm (glandular epithelia)
give examples of epithelial benign tumours
- papilloma - tumour of squamous or transitional epithelium
- adenoma - arise from glandular origin
State the name of benign mesenchymal tumour of bone
Osteoma
State the name of benign mesenchymal tumour of adipose tissue
Lipoma
State the name of benign mesenchymal tumour of cartilage
Chondroma
State the name of benign mesenchymal tumour of smooth muscle
Leiomyotoma
State the name of benign mesenchymal tumour of striated muscle
Rhabdomyotoma
What unusual benign tumours are there?
- Mixed tumours- neoplastic cells with 2 morphological patterns but from same germ layer
- Teratoma - derived from all germ layers (meso, ecto and endo) - metastatic potential
List the main types of malignant neoplasia
- carcinoma - derive from epithelial tissue (squamous, glandular and transitional)
- sarcoma - derive from connective tissue (mesodermal origin)
Give different types of carcinomas
squamous cell carcinoma sites
adenocarcinoma (glandular epithelium)
Transitional cell carcinoma (TCC)
State the name of the sarcoma of bone
osteosarcoma
State the name of the sarcoma of adipose tissue
liposarcoma
State the name of the sarcoma of cartilage
chondrosarcoma
State the name of the sarcoma of smooth-muscle
leiomyosarcoma
State the name of the sarcoma of striated muscle
rhabdomyosarcoma
What is the name of tumours of lymphoid tissue?
lymphoma
What is the name of tumours of haemopoietic cells in bone marrow
Leukaemia
What is the name of tumour derived from neuroendocrine cells, scattered in many sites?
neuroendocrine tumour
What is the name of tumours of melanocytes
Melanoma
What is the name of tumour derived from the glial cells in the CNS?
Gliomas
State the features of growth rate in benign and malignant tumours
Benign: slow
Malignant: variable (can be treated with cell-cycle specific chemotherapy agents)
- growth rates correlate with degree of anaplasia in tumour
State the features of monoclonality in benign and malignant tumours
Neoplastic proliferation derived from multiple cells (polyclonal)
- Benign and MOST malignant tumours derive from a single precursor cell = monoclonality
State the features of regulation of decay accelerating factors in benign and malignant tumours
(DAF normally degrades C3 and C5 convertase in the classical and alternative complement pathway)
- Malignant cells up regulate DAF
- Upregulation of DAF ensures that degradation of the convertase (C3 and C5) prevents the formation of the membrane attack complex (MAC; C5b-9); therefore, cancer cells cannot be killed by the MAC
State the features of regulation of local invasion and metastasis in benign and malignant tumours
Benign tumours do not invade - exception if dermatofibroma
- they are enclosed in fibrous capsule
Malignant tumours invade tissue
- they need O2 and nutrients - get it by stimulating angiogenesis
