PATH2220 Study Guide - Final Guide: Shortness Of Breath, E2F, Appendage
Neoplasia
Introduction to Neoplasia:
• Neoplasia → abnormal mass of tissue, the growth of which exceeds and is
uncoordinated with normal tissue and persists in the same excessive
manner after apparent cessation of the stimuli which evoked the change
• Disorder of cell growth triggered by a series of acquired mutations
affecting a single cell and its clonal progency
• Mutations give neoplastic cells a survival or growth advantage, resulting
in excessive proliferation that is independent of physiological growth
signals
• Components of tumours
o Parenchyma
▪ Neoplastic cells that make up tumour itself
▪ Classification is based on this
▪ Biological behavior largely determind by this
o Stroma
▪ Connectivet tissue, vessels and inflammatory cells
▪ Influences growth and repair
▪ Abundant collagenous stroma → demoplastic
• Benign tumours
o Macroscopic/microscopic features that are regarded as innocent
o Implies that it will remain localized → wont spread
o May be amenable to surgical resection
o Most patients survive → can cause morbidity and even death
o Nomenclature
▪ Mesenchymal neoplasm → attach –oma to cell type
▪ Adenoma → benign epithelial neoplasm derived from
glands
▪ Papilloma → epithelial neoplasm comprised of finger-like
projections
▪ Cystadenoma → lesions that form cystic masses
▪ Polyp → macroscopically visible projections above mucosal
surface
o Macroscopic features
▪ Well circumscribed
▪ Even cut surface
▪ No necrosis of haemorrhage
▪ May compress surrounding structures but no infiltration
▪ May have a capsule
o Microscopic features
▪ Well organized
▪ Similar appearance to normal tissue
▪ No cytological features of malignancy
• Malignant tumours
o Can invade and destroy adjacent structures
find more resources at oneclass.com
find more resources at oneclass.com
o Can spread to distant sites → metastasis
o Tumours may lead to death
o Nomenclature
▪ Tumours rising from epithelial cells → carcinoma
• Adenocarcinoma → glandular tissue
• Squamous cell carcinoma → squamous epithelium
▪ Tumours arising from mesenchymal cells → sarcoma
▪ Tumours arising from blood forming cells → leukaemia or
lymphoma
o Macroscopic features
▪ Irregular, infiltrative outlne
▪ Necrosis and haemorrhage
▪ May invade adjacent structures
o Microscopic features
▪ Disorganised architecture
▪ Nuclear pleomorphism → variation in size and shape
▪ Increased nucleus:cytoplasm ratio → nucleus bigger than it
should
▪ Hyperchromasia → too much blue staining/chromatin
▪ Mitoses
▪ Disorder, loss of polarity
• Mixed tumours
o In most human tumouts parenchymal cells show same
differentiation
o Divergent differentiation can occur → creating mixed tumour
• Teratoma
o Tumours containing mature cells from more than one germ layer
o Derives from totipotent germ cells in gonads or occasionally from
embryonic rests in midline structures
o Tumours contain a multitude of tissues
• Dysplasia
o Means disordered growth
o Typically encountered in epithelia
o Loss of uniformity
o Disorganisation
o Loss of differentiation
o Nuclear enlargement, hyperchromasia, pleomorphism
o When dysplastic changes are marked and involve thickness of
epithelium with no penetration of basement basement →
carcinoma in situ → pre-invasive neoplasm
o Once tumour cells breach basement membrane → said to be
invasive
• Local invasion
o Growth of malignant tumours accompanied by infiltration,
invasion and destruction of surrounding tissues
o Do not recognize anatomical boundaries
o May penetrate wall of a visceral organ or fungate through surface
of skin
• Metastasis
find more resources at oneclass.com
find more resources at oneclass.com
o Spread of tumour to sites that are physically discontinuous with
primary tumour
o Marks tumour as malignant
o Invasiveness of malignant tumours allows them to penetrate into
blood vessels, lymphatics and body cavities
o Some malignant tumours only metastasize infrequently
• Pathways of spread
o Lymphatic spread
▪ Most common pathway for initial dissemination
▪ Pattern of lymph node spread follows natural route of
lymphatic drainage
▪ Sentineal lymph node analysis can be used to determine
whether there is any lymphatic spread
o Haematogenous
▪ Liver and lungs are frequent sites for these deposits
o Seeding of body cavity and surfaces
▪ Peritoneal → if mucus secreting tumour, can cause
psudomyxoma peritonei
▪ Pleural
▪ Pericardial
▪ Subarachnoid
• Cancer grading
o An attempt by the histopathologists to describe the extent to
which tumour cells resemble or fail to resemble their normal
counterparts
o Different tumours have different grading schemes
▪ Two tier → low or high grade
▪ Three tier → well/moderately/poorly differentiated
o Some schemes are purely qualitative → others are more
quantitative
• Cancer staging
o Assessment of clinical gravity of disease
o TNM staging
▪ T → tumour → size, extent of spread
▪ N → nodal status → number, groups, size etc.
▪ M → metastasis → distant organs
• Predisposing factors
o Genetic
▪ Autosomal dominant inherited cancer syndromes
▪ Defective DNA repair syndromes and resulting DNA
instability
▪ Familial cancers → colon, breast, ovary, melanoma
o Lifestyle factors/choices → i.e. smoking
o Preacancerous conditions
▪ Non-neoplastic → ulcerative colitis, chronic gastritis
▪ Neoplastic → benign neoplasm
o Radiation
▪ UV → squamous and basal cell carcinoma melanoma
find more resources at oneclass.com
find more resources at oneclass.com
