Define neoplasia and neoplasm: - Answer Neoplasia is a disorder of altered cell
differentiation and growth. Neoplasm is the "new growth."
Define proliferation and differentiation: - Answer Proliferation, a process of cell division,
is an adaptive process for new cell growth to replace old cells or when additional cells
are needed. Differentiation is the process in which cells become more specialized with
each mitotic division.
What are the 3 main groups of cells that proliferate? - Answer (1) well-differentiated
neurons and cells of skeletal and cardiac muscles that rarely divide and reproduce; (2)
progenitor or parent cells that continue to divide and reproduce, like blood, skin, and
liver cells; (3) undifferentiated stem cells that can enter the cell cycle and produce large
number of progenitor cells if needed.
What are progenitor cells? - Answer The more specialized cells are unable to divide, so
these cell populations rely on progenitor or parent cells of the same lineage that have
not yet differentiated to the extent that they have lost their ability to divide. They have
enough differentiation so the daughter cells are limited to the same cell line, but not
quite differentiated enough to prohibit active proliferation.
What are the benefits of the stem cell? - Answer Stem cells remain dormant until they
are needed. When needed, they can divide, produce other stem cells, and carry out the
functions of the differentiated cell. Two important properties that stem cells possess are
self-renewal and potency. Self-renewal means the stem cell can undergo numerous
mitotic divisions while maintaining an undifferentiated state. Potency describes the
differentiation potential of stem cells.
What is a polyp? - Answer A polyp is a growth that projects from a mucosal surface,
such as the intestine. A polyp can be benign or malignant.
Explain metastasis and how it occurs: - Answer The multi-step process of metastasis
occurs as follows: a cancer cell must break loose from the primary tumor, invade the
surrounding extracellular matrix, gain access to a blood vessel, survive its passage in
the bloodstream, emerge at a favorable location, invade the surrounding tissue, begin to
grow, and establish a blood supply.
What are the two broad categories of malignant neoplasms? - Answer Solid tumors and
hematologic cancers
Explain what carcinoma in situ is? - Answer Carcinoma in situ is a localized preinvasive
lesion. These can typically be surgically removed or treated, and recurrence is less
likely.