Chapter 7 Flashcards
(110 cards)
2 basic tissue components of benign and malignant neoplasms; which component typically gives rise to the neoplastic cells?
Parenchyma = generally gives rise to neoplatic cell component — this is what classification of tumors is based on
Reactive stroma = supportive tissue skeleton on which the parenchymal component resides - responsible for growth and spread
How is a mixed tumor of the salivary gland different from an adenoma of the colon?
Mixed tumor of salivary gland = pleiomorphic adenoma (benign) — contains more than one neoplastic cell type, usually derived from one germ layer
Adenoma of the colon = benign epithelial neoplasm derived from glands, may form adenomatous polyp
How is a cystic teratoma of the ovary fundamentally different from a mixed tumor of the salivary gland?
Primary difference is that teratomas may come from all 3 germ layers, while mixed tumors usually come all from same germ layer, even if different cell types are involved
Hallmark of malignancy characterized by lack of differentiation
Anaplasia
4 grades of differentiation
Well differentiated — closely resembles parent tissue
Moderately differentiated — features of the original tissue type identifiable but not in normal pattern, with additional atypia
Poorly differentiated — small minority of cell constituents allow ID of parent tissue; associated with cellular anaplasia
Undifferentiated — cannot discern parent tissue of origin; always associated with anaplasia
Histopathologic criteria used when classifying something as “anaplastic”
Pleomorphism
Abnormal nuclear morphology
High mitotic rate
Loss of polarity
Additional blood vessel formation with central areas of necrosis
Metaplasia vs. dysplasia
Metaplasia = replacement of one type of cell with another; found in association with tissue damage, repair, and regeneration
Dysplasia = disordered growth; encountered principally in epithelia, characterized by loss in uniformity of individual cells as well as loss in their architectural orientation
Define carcinoma in situ
Dysplastic changes are marked and involve full thickness of epithelium, but lesion does not penetrate the basement membrane
Carcinoma in situ is best characterized as ________
Pre-neoplastic (argument could be made for “benign” as well)
Most common histopathologic features used to assess rate of growth in a neoplasm
Slow growing cancers typically have capsule (rim of compressed fibrous tissue)
Malignant/rapidly growing tumors are typically poorly demarcated and lack well-defined cleavage plane; some have pseudoencapsulation (rows of cells penetrating margin and infiltrating adjacent structures)
Pathologic features that individually (and almost always in aggregate) distinguish malignant from benign tumors
Atypical structure with some lack of differentiation (anaplasia)
Erratic rate of growth; mitotic figures may be numerous and abnormal
Locally invasive, infiltrating surrounding tissue
Metastasis
2 examples of malignancies that rarely metastasize
Gliomas
Basal cell carcinomas
3 major pathways by which metastasis may occur
Direct seeding of body cavities or surfaces
Lymphatic spread
Hematogenous spread
Describe metastasis by direct seeding of body cavities/surfaces
May occur whenever a malignant neoplasm penetrates into a natural “open field” lacking physical barriers
Most often involves peritoneal cavity (can also be pleural, pericardial, subarachnoid, joint spaces, etc.)
Describe pattern of lymphatic spread in the metastasis of breast vs. lung cancers
Breast —> axillary nodes or internal mammary arteries
Lung —> perihilar tracheobronchial and mediastinal nodes
Carcinomas typically metastasize via lymphatic spread, however there are some exceptions. What are 4 carcinomas that tend to metastasize via hematogenous spread?
Renal cell carcinoma - via renal v. to IVC
Hepatocellular carcinoma - via hepatic v.
Follicular carcinoma of thyroid
Choriocarcinoma
First node in a regional lymphatic basin that receives lymph flow from the primary tumor
Sentinal node
The most common tumor of men in the US and most of developed world is prostate cancer, but in certain countries or regions (most located in developing world), cancers of the liver, stomach, esophagus, bladder, lung, oropharynx, and immune system rise to the top of the list.
Similarly, the incidence of breast cancer is generally much higher in women in developed countries than in most parts of the developing world.
What are some probable reasons for the difference in incidence in prostate and breast cancers?
Environmental influences likely underlie most differences in incidence:
Infectious agents like HPV Smoking Alcohol consumption Diet Obesity Reproductive history Environmental carcinogens
Occupational cancer associated with arsenic exposure (by-product of metal smelting, exposure to medications/herbicides/fungicides)
Squamous cell carcinoma of skin
Lung carcinoma
Occupational cancer associated with asbestos exposure (found in construction of older buildings, friction materials, roofing tiles, floor papers, etc)
Lung, esophageal, gastric, and colon carcinoma; mesothelioma
[note that lung carcinoma more commonly occurs than mesothelioma]
Occupational cancer caused by benzene exposure (component of light oil; used in dry cleaning, printing, paint, rubber, detergents)
Acute myeloid leukemia
Occupational cancer due to beryllium exposure (missile fuel, space vehicles, nuclear reactors)
Lung carcinoma
Occupational cancer due to cadmium exposure (yellow pigments and phosphors; found in solders, batteries, metal platings, coatings)
Prostate carcinoma
Occupational cancer due to chromium exposure (metal alloys, paints, pigments, preservatives)
Lung carcinoma
