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Pathology: Week 3 Lecture notes
Neoplasms - (tumors) The abnormal, excessive and uncontrolled multiplication of cells with the formation of mass or new growth of tissue. Can either be benign or malignant, and they divide when they should not be Tumors - Another word for a NEOPLASM Clinical features of benign neoplasms - Slow growth, unusual ulceration, unusual hemorrhaging, and no evidence of metastasis Clinical features of malignant neoplasms - Rapid growth, frequent ulceration, frequent hemorrhaging, and frequent evidence of metastasis Histological features of benign neoplasms - Good resemblance to tissue origin, fairly uniform cell size and shape, very few & all normal mitotic figures (chromosomes), no invasion of blood vessels, no dysplasia in adjacent tissues Histological features of malignant neoplasms - Often poor resemblance to tissue origin, highly variable cell size and shape, often numerous & frequently abnormal mitotic figures (chromosomes), often present invasion of blood vessels, sometimes dysplasia in adjacent tissues Dysplasia - Invasion Characteristics of benign neoplasms - Grown by expansion, do not migrate, generally do NOT return after surgical removal, do not generally cause extensive tissue damage, do not generally cause whole body changes, resemble tissue of origin, generally not fatal Expansion - Pushing surrounding tissue aside Metastasize - Transfer of a disease from its primary site to a distant location Hypertrophy - An enlargement of a tissue or organ due to the increase in the size of the cells composing it. NOT TO BE CONFUSED with a neoplasm, which is uncontrolled cell proliferation Physiological hypertrophy example - Breasts and uterus enlarge in response to pregnancy
Pathological hypertrophy example - Myocardial cells increase in size increasing the size of the heart muscles in response to high blood pressure Compensatory hypertrophy example - Increase in size due to some physical defect (usually in paired organs). Example: Removal of a kidney increases the size of the other Epithelial tissue - Tissue of closely packed cells in one or more layers that form the coverings of the body Examples of benign epithelial neoplasms - Adenoma, papilloma, nevus, polyp Adenoma - A benign tumor of glandular origin (originates from cells used in secretion) Can become malignant over time at which time becomes an adenocarcinoma Think of the pituitary gland Papilloma - A tumor that grows as finger-like projections from epithelial tissue Nevus - Chronic lesions of the skin (Birthmarks and moles) Polyp - A growth or mass of tissue that protrudes from a mucous membrane Found during colonoscopies Connective tissue - Tissue generally involved in structure and support. Composed of cells and non-living matrix. Harder to cut thru than epithelial (think BONEZ) Examples of benign connective tissue neoplasms - Osteoma, condrioma, lipoma, angioma, fibroma Osteoma - A new piece of bone growing on existing bone (usually the skull) Chondroma - Cartilage tumor. Tumor cells resemble normal cells and produce an excess of cartilaginous matrix Lipoma - Composed of fairy tissue. Most common form of soft tissue tumor. Soft, painless, and generally small Angioma -
Characteristics of malignant neoplasms - Grow by infiltration, metastasize creating secondary foci, often reoccur when removed surgically, cause extensive tissue damage, can cause total body changes, tumor does NOT resemble surrounding tissue, lethal unless treated Foci - The region of a localized bodily infection or disease Secondary foci - A satellite location of a region of a localized bodily infection or disease Ex. of malignant epithelial tissue neoplasms - Melanoma, squamous cell carcinoma, adenocarcinoma, transitional cell carcinoma, basal cell carcinoma Melanoma - Cancer of melanocytes (pigment cells). Usually in the skin but also in the bowel and eyes. Most common in caucasian males. Most deadly form of skin cancer (75% of skin cancer deaths) Melanocytes - Pigment cells Squamous cell carcinoma - Malignant tumor of the squamous epithelium. May occur in many different organs where squamous epithelium is found, including the skin, lips, mouth, esophagus, bladder, prostate, lungs, vagina, and cervix Adenocarcinoma - Malignant tumor originating from or having secretory properties similar to glandular tissue Secretory - Secretes stuff and things and all that jazz Transitional cell carcinoma - Originates in the epithelial cells of the kidney, bladder or uterus. Most common type of bladder cancer Basal cell carcinoma - Cells that form the lowest layer of the epidermis (stratum basal) become altered and proliferate into the dermis and upper epidermal layers. Most common type of skin cancer Stratum basale - The lowest layer of the epidermis (see basal cell carcinoma) Ex. of malignant connective tissue neoplasms - Osteosarcoma, chondrosarcoma, liposarcoma, angiosarcoma, fibrosarcoma, lymphoma Osteosarcoma -
Malignant bone cancer. Soft connective tissue changes to form humoral bone. Most common type of bone cancer. Most cases occur around the knee Chondrosarcoma - Malignant cartilage tumor. Considered a form of bone cancer. Affects primarily adults. Liposarcoma - Malignant tumor that arises in fat cells in deep soft tissue such as the thigh. Generally large bulky tumors with smaller satellite tumors. Very rare Angiosarcoma - Tumors originating from the epithelial line of blood vessels (REMEMBER blood is a connective tissue). Most commonly found in the face and scalp region. Most are cutaneous angiosarcomas (found in the skin) Fibrosarcoma - Malignant tumor originating in the fibrous connective tissue. Sometimes resemble normal cells of the tissue even secreting collagen Lymphoma - Malignancy of lymphoid tissue (composed of lymphocytes: white blood cells). Often originate in the lymph nodes. Hodgkins (Reed-Sternberg) and Non-hodgkins are based on the specific type of lymphocyte that they affect Ex. of malignant muscle tissue neoplasms - Rhabdomyosarcoma, leiomyosarcoma Rhabdomyosarcoma - Arises from rhabdoblasts (immature muscle cells). Instead of becoming striated (cardiac or skeletal) muscle the cells grow out of control. Fast growing and prevalent in children (muscles are still developing) Rhabdoblasts - Immature muscle cells. KNOCK IT OFF YOU LITTLE RHABDOBASTARDS! Leiomyosarcoma - Malignant tumors of non-striated (smooth) muscle. Most common in the stomach and small intestine. Very rare. One of the rarest types of soft tissue cancer. Soft tissue cancer itself is very rare. This stuff is so rare, it's still MOOIN'! Ex. of malignant nervous tissue neoplasms - Glioma Glioma - Originates in the brain or spinal cord. Arises from glial cells. Most common in the brain Post mortem conditions asso. w/ neoplasms - Emaciation, discoloration, hemorrhage, tissue deformation, dehydration, cachexia
Anemia - A decrease in the number of erythrocytes (RBCs), hemoglobin, or both. Can be primary or secondary Primary (pernicious) Anemia - A rare blood disorder characterized by the inability of the body to properly utilize vitamin B12, which is essential for the development of RBCs. Most cases result from the lack of the gastric protein known as intrinsic factor, without which vitamin B12 cannot be absorbed Secondary Anemia - Anemia resulting from the course of other affections such as hemorrhage, or inadequate diet. Blood loss due to hemorrhage can be slow such as in the case of cirrhosis of the liver. Affects accumulate over several days or even weeks Hematopoietic disorders - Disorders in the formation of the components of the blood in the bone marrow Ex. of hematopoietic disorders - Leukemia, polycythemia vera Leukemia - Disease characterized by the appearance of great numbers of immature and abnormal white blood cells (cancer of the blood or bone marrow). Acute form is prevalent in children Polycythemia vera - An increase in the total RBC mass due to bone marrow abnormality. Usually accompanied by increased production of WBCs and platelets. Increased likeliness of blood clots results in some cases but often asymptomatic Ex. of Bleeding disorders - Hemophilia, pupura, thrombocytopenia Hemophilia - An inherited hemorrhagic disease characterized by excessive and sometimes spontaneous bleeding. Missing a key clotting factor. Prevalent in European royalty as we can see in their WELL KEPT RECORDS Purpura - A condition in which spontaneous bleeding occurs in the subcutaneous tissues, causing the appearance of purple patches on the skin. Causes cary and include vascular, platelet, and coagulation disorders as vitamin C deficiencies. Similar in appearance to petechiae only larger Thrombocytopenia - Relatively low platelet counts in the blood. Multiple causes include vitamin deficiencies, sepsis (pathogens in the blood), genetic factors, certain drugs, and leukemia. Bruising and purpura can result as blood has difficulty clotting
