Lecture 8 - Neoplasia

Question 1

Benign vs. Malignant:

-Benign

Answer 1

• “innocent acting”, if left untreated, tumor should not kill patient
• remain localized (not metastasize)
• well circumscribed and grows by expansive growth (pushing boarders)
• microscopically look like tissue of origin

Question 2

Benign vs. Malignant:

-Malignant

Answer 2

• grow slowly, potentially more harmful, fatal if left unchecked
• potential for metastasis = spread of tumor to different sites
• grows via invasive growth, jagged boarders grow into tissue/organ
• microscopically the more malignant, the less it looks like tissue of origin

Question 3

Carcinoma

Answer 3

• malignant

- primary tissue that gives rise to malignant tumor is epithelial tissue

Question 4

Sarcoma

Answer 4

• malignant

- primary tissue that gives rise to malignant tumor is muscle/connective tissue

Question 5

Lymphoma

Answer 5

• malignant

- primary tissue that gives rise to malignant tumor is solid lymphoid tissues (ex: lymph nodes, spleen, thymus)

Question 6

Leukemia

Answer 6

• malignant

- primary tissue that gives rise to malignant tumor is hematopoietic tissue (tumor that begins in bone marrow)

Question 7

Nomenclature for Benign tumor

Answer 7

• almost everything else that ends in -oma

Question 8

Epithelial Tissue tumor nomenclature

Answer 8

• squamous cell papilloma = upper layer of skin, benign
• squamous cell carcinoma = upper layer of skin, malignant
• basal cell carcinoma = bottom, boxy, immature layer of skin, malignant (common does not metastasize)
• adenoma = adeno = gland, benign
• adenocarcinoma = gland, malignant (breast cancer)

Question 9

Connective Tissue tumor nomenclature

Answer 9

• fibroma / fibrosarcoma = fibrous (collagen/filling)
• lipoma / liposarcoma = fat (“lipo”)
• chondroma / chondrosarcoma = cartilage (“chondro”)
• osteoma / osteosarcoma = bone (“osteo”) [malignant bone tumors more common in children’s growing bones]

Question 10

Endothelial Tissue tumor nomenclature

Answer 10

• hemangioma / hemangiosarcoma = heme = blood, angio = vessel
• lymphangioma / lymphangiosarcoma = lymph vessels

Question 11

Muscle tumor nomenclature

Answer 11

• leiomyoma / leiomyosarcoma = smooth (“leio”) muscle (“myo”) [ex: GI tract, uterus]
• rhabdomyoma / rhabdomyosarcoma = striated (“rhabdo”) muscle [ex: cardiac and skeletal, malignancies rare, found more in children]

Question 12

Exceptions to tumor nomenclature

Answer 12

• Malignancies that don’t follow the rules
• Mesothelioma = malignant tumor of pleura (lungs). Commonly due to asbestos; grows all around and into lungs.
• Melanoma = malignant tumor of melanocytes (skin). Benign form = nevus (mole)
• Seminoma = more common malignant tumor of the testicle
• Glioma = malignant tumor of brain, primary cell is a neuron in the brain (did not metastasize there).

Question 13

Non-tumor masses:

Answer 13

• overgrowth of cells but are not neoplasms
• Hamartoma = mass of disorganized tissue indigenous/native to where its found. (ex: collection of vessels, or cartilage in the lung)
• Choristoma = heterotopic rests = microscopic collection of tissue in the wrong place

Question 14

Dyplasia

Answer 14

• disorderly/abnormal but non-neoplastic growth; something is stimulating it to grow in such a way (virus, environmental); precancerous
• often qualified/graded like tumors
• used predominantly to describe epithelial tissues
• less that full thickness = reversible
• full thickness = can span width of organ/tissue but are “in situ” (confined to that specific area/organ/tissue)

Question 15

Staging T, N, M systems

Answer 15

• staging helps determine prognosis by comparing staging to other people who had a similar tumor
• T = primary tumor size (T1 = small tumor)
• N = lymph node involvement, how many affected (N1 = 1 lymph node)
• M = metastasis (M0 = no metastasis, M1 = metastasis)