06肿瘤

The Concept of Tumor
• The neoplasia results from genetic alterations that are passed down to the progeny of the tumor cells. These genetic changes allow excessive and unregulated proliferation that becomes autonomous • The entire population of neoplastic cells within an individual tumor arises from a single cell that has incurred genetic change, and hence tumors are said to be clonal
Squamous cell carcinoma of the ankle (left) Malignant melanoma of the ankle (right)
Fibrous adenoma of the breast
Renal cell carcinoma
Osteosarcoma
Parenchyma and Mesenchyma (stroma)
• Stem cell – asymmetric replication • Cancer stem cell or tumor-initiating cell
Papilloma of the skin. It is a benign tumor. Note the parenchyma and stroma of the tumor.
Breast carcinoma. It is a malignant tumor. Note the parenchyma and stroma of the tumor.
– circumscribed or infiltrative (invasive) – encapsulated or unencapsulated
Multiple leiomyoma of the uterus (left) and lipoma (right)
Villiform adenoma of the colon (right)
The Difference between Neoplastic and non-Neoplastic Growth
• Monoclonality • Abnormal morphology, metabolism and function • Excessive, unregulated and autonomous growth • Heritable genetic changes • Harm to host
Atypia and dysplasia
• Atypia refers to the disimilated extent to which neoplastic parenchymal cells compare with the corresponding normal parenchymal cells, both morphologically and functionally • Dysplasia is a term that literally means disordered growth. Dysplasia is encountered principally in epithelia, and it is characterized by a constellation of changes that include a loss in the uniformity of the individual cells as well as a loss in their architecturumor
• "A neoplasm is an abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of the normal tissues and persists in the same excessive manner after cessation of the stimuli which evoked the change." British oncologist Willis 1952
Progression and Heterogeneity
Tumor progression and generation of heterogeneity. New subclones arise from the descendants of the original transformed cell by multiple mutations. With progression he tumor mass becomes enriched for variants that are more adept at evading host defenses and are likely to be more aggressive.
Differentiation
• Differentiation refers to the extent to which neoplastic parenchymal cells resemble the corresponding normal parenchymal cells, both morphologically and functionally • In general, benign tumors are well differentiated • Malignant tumors are poorly differentiated
Anaplasia and Anaplastic Neoplasm
• Lack of differentiation is called anaplasia • Malignant neoplasms that are composed of poorly differentiated cells are said to be anaplastic
Nomenclature
• Neoplasia means "new growth," and a new growth is called a neoplasm. • Tumor originally applied to the swelling caused by inflammation, but the nonneoplastic usage of tumor has almost vanished; thus, the term is now equated with neoplasm. • Oncology is the study of tumors or neoplasms (Greek oncos = tumor).
Morphologic Changes of Atypia
• Pleomorphism
– cells and the nuclei
• • • • • •
Hyperchromatic nuclei Increased nuclear-to-cytoplasm ratio Mitoses (atypical, bizarre mitotic figures) Loss of polarity Tumor giant cells Necrosis
Menigioma (right)
Breast carcinoma
Mucinous papillary cystadenoma of the ovary
Neurofibroma in scalp
Osteosarcoma in the humeral bone Left is X-ray and right is gross photo
anaplasia
hyperchromasia
increased N:C ratio
tumor giant cells
abnormal mitotic figures
Tumor giant cells
Growth and Spreading
A tumor arises from a single cell i.e. monoclonal
Rates of growth doubling time growth fraction
cell death angiogenesis
Rate of growth
• The rate of growth of a tumor is determined by three main factors:
• Polyclonality • Normal morphology, metabolism and function • Limited growth • No genetic alteration • Benefit to host
The Gross Features of Tumors
• • • • • Size and number Form Color and consistence Hardness Interface with surrounding tissue
Neoplasia
By GANDI LI & QIAO ZHOU
Department of Pathology West China Hospital Sichuan University
Incidence and Mortality of Cancer
• Cancer is the first leading cause of death in China according to the public health statistic data in 2008. • The common malignant tumors in China are from lung, liver, stomach, colon, esophagus, nasopharynx, breast, cervix, as well as leukemia and lymphoma.