B2.031 Histopathology of Neoplasia Flashcards
what is a tumor parenchyma?
neoplastic cells within the tumor mass
what is reactive stroma?
non-neoplastic connective tissue, blood vessels, immune cells, etc. within the tumor mass
what are the two components of a tumor?
tumor parenchyma
reactive stroma
what is differentiation?
degree of resemblance of neoplastic cells to the cell of origin
what does “grading of neoplasms mean”?
describing neoplasms based on their level of differentiation (well differentiated = benign, poorly differentiated = malignant)
what is pleomorphism?
variation in size and shape of cells
what is anaplasia?
lack of differentiation (malignant)
what is invasion?
growth of neoplastic cells beyond the site of origin
what categorizes invasion in epithelial neoplasms?
growth beyond the basement membrane
what is metastasis?
discontinuous spread of neoplastic cells to a site distant from the site of origin
what are some key features of a benign neoplasm?
localized
incapable of invasion
incapable of metastasis
USUALLY good clinical behavior
what are some key features of a malignant neoplasm?
capable of invasion into surrounding tissue
capable of metastasis
USUALLY poor clinical behavior (death most often due to spread)
give an example of a benign neoplasia with a poor clinical outcome
when in intracranial space, any growth can result in death due to compression
give an example of a malignant neoplasia with a good clinical outcome
basal cell carcinomas rarely metastasize despite being malignant
how are benign neoplasms usually named?
-oma suffix adenoma (glands) chondroma (cartilage) lipoma (adipose) leiomyoma (smooth muscle)
how are epithelial malignant neoplasms named?
-carcinoma
how are mesenchymal malignant neoplasms named?
-sarcoma
what are hematopoietic malignant neoplasms called?
lymphoma (lymph nodes)
leukemia (bone marrow, blood)
what are melanocytic malignant neoplasms called?
melanoma
what is a mixed tumor?
neoplasm with divergent differentiation
due to autonomous proliferation
often a mixture of epithelial and mesenchymal cells
what is a teratoma?
neoplasm of germ cells with derivatives of different germ layers
what are histologic features of benign neoplasms?
smooth margins circumscribed may be encapsulated uniform composition good differentiation low mitotic activity lack of hemorrhage and necrosis
what are histologic features of malignant neoplasms?
infiltrating margins
variegated composition (hemorrhage and necrosis)
lack of resemblance to cell/tissue of origin
cellular atypia
anaplasia
mitotic activity (atypical mitoses)
what is desmoplasia?
fibrotic host response to infiltrating neoplasms
what is dysplasia?
disordered growth of neoplastic epithelial cells, confined by the basement membrane
what is another name for dysplasia?
intraepithelial neoplasia (IN)
how is dysplasia classified?
by degree of morphologic atypia
what is the furthest progression of dysplasia called?
carcinoma in situ
characterize a carcinoma in situ
all cellular features of carcinoma, but still confined by basement membrane
do dysplasias always progress to malignancies?
no, can spontaneously correct
what screening tool has greatly reduced cervical cancer death rates?
pap smear screening for dysplasia
how often do benign neoplasms transform to malignant neoplasms?
rarely
