4 morphological charact. that diff. between benign & malignant tumors
- differentiation
- local invasion
- growth of transformed cells
- growth pattern
Differentiation definition
- when parenchymal cells look like normal cells, morphologically and functionally
Benign tumors are…
Well differentiated
Malignant tumors are
Well diff-poorly diff
Dysplasia
- disordered growth
- in epithelia
- loss of cell uniformity in individual cells and architectural orientation
- can be preneoplastic
Anaplasia
- loss of cell diff
- can be called dedifferentiation
- reversion of cells to more primitive form
Cytologic characteristics of anaplasia
- pleomorphism
- abnormal nuclear morph
- lg. nucleoli (incr. protein synthesis)
- mitotic figures & abnormal incr. in # of mitoses
- loss of polarity
- formation of tumor giant cells
Pleomorphism definition
Variation in size & shape of cells
Characteristics variations of pleomorphisms
- nuclear:cytoplasmic
- anisokaryosis & poikilokaryosis
- anisocytosis & poikilocytosis
Abnormal mitoses
- large #s of mitoses
- mitotic figures (tripolar, quadripolar, multipolar)
Loss of polarity
- cell orientation disturbed
- cells grow in disorganized fashion
Tumor giant cells
- lg. polymorph. nucleus or multiple variant nuclei
- not same as normal giant cells
Functional differentiation
- better diff.= cell will more likely resemble normal cells
- anaplasia incr.= enzymes and specialized pathways may be lost-> simplification (functional)
Sign of squamous cell carcinomas
Keratin pearls
2 types of functional differentiation
- some elaborate fetal proteins not produced. by normal counterpart cells
- some cancers of non-endocrine origin can secrete endocrine-like hormones
Functional abnormalities can cause…
Paraneoplastic syndromes
Growth of benign tumors
- expansile, but localized to site of origin
- no capacity to invade or metastasize
- develop CT capsule
Malignant tumor growth
- grow via progressive infiltration
- invasion/destruction of surrounding tissue
- typically not encapsulated
Carcinoma in situ
Malignant tumor that hasn’t invaded beyond BM
Factors involved in tissue’s resistance to tumor invasions
- physiochemical characteristics of matrix
- stability & low turnover of some tissues
- elaborate inhibitory substances
Metastasis indicates
Malignancy
Types of metastasis
- seeding of body cavities
- lymphatic spread
- hematogenous
Lymphatic metastasis is common in
carcinomas
Hematogenous metastasis
- uses venous flow
- used by sarcomas
- if arterial, then can occur in pulmonary capillaries, arterio-venous shunts, or pulmonary mets
