clinical pathology Flashcards
cancer: define terms associated with cancer including, cancer, neoplasm, tumour, metastasis, carcinogen; list features which distinguish benign from malignant tumours, and pathological features that may predict prognosis, recall examples of carcinogens and the cancers they may cause, recall principles of cancer screening
define tumour
any kind of mass-forming lesion
types of tumour
neoplasm, hamartoma, inflammatory
define neoplasm
autonomous growth of tissue which has escaped normal constraints of cell proliferation
types of neoplasm
benign and malignant
define benign
remains localised
define malignant
invades locally and/or spreads to distant sites
define cancers
malignant neoplasms
define hamartoma
localised, benign overgrowth of one or more mature cell types (i.e. lung)
hamartoma abnormalities
architectural not cytological as contains malformed normal tissue
define heterotopia
normal tissue found in place not normally present (i.e. pancreas in stomach wall)
how are neoplasms classified
based on cell origin and whether benign or malignant
define teratoma
tumour derived from germ cells
what do teratomas contain
immature/mature/cancerous tissue derived from all 3 germ cell layers
4 differences between benign and malignant tumours
invasion, metastasis, differentiation, growth pattern
benign vs malignant: invasion
malignant is a direct extension into adjacent tissue/other structure by breaking through basement membrane
benign vs malignant: metastasis
all malignant tumours have capacity to metastasise and spread via blood to other parts of body
define cytological
how much do the tumour cells resemble the cells of its derived tissue, including function
benign vs malignant: differentiation
tumour cells have larger nuclei so higher nuclei:cytoplasmic ratio and more (abnormal) mitoses, as well as marked nuclear pleomorphism (variability in nuclear size and shape)
define architectural
how much does the tumour architecture resemble derived tissue
benign vs malignant: growth pattern
tumours have less well defined architecture, benign grow relatively slowly
can a benign tumour turn into a malignant tumour
yes
5 routes of malignant neoplasm (cancer) spread
direct extension, haematogenous, lymphatic, transcoelomic, perineural
malignant neoplasm (cancer) spread: direct extension
associated with stromal response to tumour (includes fibroblastic proliferation “desmoplastic response”, vascular proliferation angiogenesis and immune response)
malignant neoplasm (cancer) spread: haematogenous
usually venules and capillaries as thinner walls; most sarcomas metastasise first via blood stream
malignant neoplasm (cancer) spread: lymphatic
via lymphatics to lymph nodes and beyond; spread pattern dictated by normal lymphatic drainage of organ; most epithelial cancers metastasise first via lymphatics
malignant neoplasm (cancer) spread: transcoelomic
seeding of body cavities; commonest are pleural (intrathoracic) and peritoneal (intra-abdominal)
malignant neoplasm (cancer) spread: perineural
via nerves
3 methods to assess tumour spread
clinically, radiologically, pathologically
describing tumour spread (TNM)
tumour (size/extent of local invasion), nodes (no. lymph nodes involved), metastases (presence of distant metastases)
prognosis of tumour: grade and spread
grade (how differentiates tumour is) is less important for prognosis than stage (how far tumour has spread using TNM)
define carcinogen
agent that causes genetic damage and induces neoplastic transformation of cells
chemial carcinogen types
inducers, promoters and direct
radiation carcinogen types
UV, ionising EM
microbial carcinogen types
DNA oncogenic viruses, RNA viruses, bacteria (e.g. Helicobacter)
