Chapter 7 – Neoplasia: Nomenclature Flashcards
What is Neoplasia?
Neoplasia means “new growth,” and a new growth is called a neoplasm.
Tumor originally
applied to the swelling caused by inflammation, but the non-neoplastic usage of tumor has
almost vanished; thus, the term is now equated with neoplasm
What is Oncology?
Oncology (Greek oncos =
tumor) is the study of tumors or neoplasms.
What is the closes accurate definition of the term neoplasia?
Although all physicians know what they mean when they use the term neoplasm, it has been
surprisingly difficult to develop an accurate definition. The eminent British oncologist Willis [2]
has come closest:
“A neoplasm is an abnormal mass of tissue, the growth of which exceeds and
is uncoordinated with that of the normal tissues and persists in the same excessive manner
after cessation of the stimuli which evoked the change.”
We know that the persistence of
tumors,even after the inciting stimulus is gone, results from genetic alterations that are passed
down to the progeny of the tumor cells.
These genetic changes allow excessive and
unregulated proliferation that becomes autonomous (independent of physiologic growth
stimuli), although tumors generally remain dependent on the host for their nutrition and blood
supply. As we shall discuss later, the entire population of neoplastic cells within an individual
tumor arises from a single cell that has incurred genetic change, and hence tumors are said to
be clonal.
When can you say that a tumor is benign?
A tumor is said to be benign when its microscopic and gross characteristics are considered
- relatively innocent,** implying that *it will remain localized, it cannot spread to other sites, and it is
- generally amenable to local surgical removal;* the patient generally survives.
It should be noted,
however, that benign tumors can produce more than localized lumps, and sometimes they are
responsible for serious disease.
What is cancer?
Malignant tumors are collectively referred to as cancers, derived from the Latin word for crab,
because they adhere to any part that they seize on in an obstinate manner, similar to a crab.
\
When do you say that a tumor is malignant?
Malignant, as applied to a neoplasm, implies that the lesion can invade and destroy adjacent
structures and spread to distant sites (metastasize) to cause death.
Not all cancers pursue so
deadly a course. Some are discovered early and are treated successfully, but the designation
malignant always raises a red flag.
All tumors, benign and malignant, have two basic components:
- (1) clonal neoplastic cells tha tconstitute their parenchyma and
- (2) reactive stroma made up of connective tissue, blood vessels, and variable numbers of macrophages and lymphocytes.
Although the neoplastic cell largely determine a tumor’s behavior and pathologic consequences, their growth and evolution
is critically dependent on their _________
stroma.
What is the requisite for the tumor cells to live and divide?
An adequate stromal blood supply is requisite for the
tumor cells to live and divide, and the stromal connective tissue provides the structural
framework essential for the growing cells.
In addition, there is cross-talk between tumor cells
and stromal cells that directly influences the growth of tumors.
What is desmoplasia?
In other cases the parenchymal cells
stimulate the formation of an abundant collagenous stroma,referred to asdesmoplasia
In some tumors, the stromal
support is scant and so the neoplasm is soft and fleshy.
What is scirrhous?
Some
- demoplastic tumors—for example, some cancers of the female breast—are *stony hard or
- *scirrhous.**
The nomenclature of tumors and their biologic behavior are based primarily on the
_______________
parenchymal component
How do you name the benign tumors?
In general, benign tumors are designated by attaching the suffix -oma to the cell of origin.
Tumors of mesenchymal cells generally follow this rule.
a benign tumor arising in
fibrous tisssue is called a________
fibroma
What is the name for benign cartiliginous tumor?
chondroma
How do you name benign epithelial tumors?
In
contrast, the nomenclature of benign epithelial tumors is more complex. These are variously
classified, some based on their cells of origin, others on microscopic pattern, and still others on
their macroscopic architecture.
What is an adenoma?
Adenoma is applied to a benign epithelial neoplasm derived from glands, _although they may or
may not form glandular structures_
On this basis, a benign epithelial neoplasm that arises from
renal tubular cells growing in the form of numerous tightly clustered small glands would be
termed an adenoma, as would a heterogeneous mass of adrenal cortical cells growing as a
solid sheet
What is a papilloma?
- *Benign epithelial neoplasms** producing microscopically or macroscopically visible
- finger-like or warty projections** from epithelial surfaces are referred to as *_papillomas._
What are cystadenomas?
Those that
form large cystic masses, as in the ovary, are referred to as cystadenomas.
What arepapillary
cystadenomas.?
Some tumors
-
produce papillary patterns that protrude into cystic spaces* and are called **papillary
cystadenomas. **
What is a polyp?
When a neoplasm, benign or malignant, produces a macroscopically visible
projection above a mucosal surface and projects, for example, into the gastric or colonic lumen,
it is termed a polyp ( Fig. 7-1 ).
Colonic polyp. A, This benign glandular tumor (adenoma) is projecting into the
colonic lumen and is attached to the mucosa by a distinct stalk. B, Gross appearance of several colonic polyps.
How are malignant tumors named?
The nomenclature of malignant tumors essentially follows the same schema used for benign
neoplasms, with certain additions
Malignant tumors arising in mesenchymal tissue are usually called ***_sarcomas (Greek sar = fleshy)_***, because they have little connective tissue stroma and so are fleshy (e.g., fibrosarcoma, chondrosarcoma, leiomyosarcoma, and rhabdomyosarcoma).
Malignant neoplasms of epithelial cell origin, derived from any of the three germ layers, are
called carcinomas.
What is sarcoma?
**Malignant tumors arising in mesenchymal tissue** are usually called sarcomas (Greek **sar = fleshy**), because **they have little connective tissue stroma** and so **are fleshy (e.g., fibrosarcoma, chondrosarcoma, leiomyosarcoma, and rhabdomyosarcoma**).
What are carcinomas?
Malignant neoplasms of epithelial cell origin, derived from any of the three germ layers, are
called carcinomas.
Thus, cancer arising in the epidermis of ectodermal origin is a carcinoma, as
is a cancer arising in the mesodermally derived cells of the renal tubules and the endodermally
derived cells of the lining of the gastrointestinal tract
What is the further classification of carcinoma?
Carcinomas may be further qualified.
Squamous cell carcinoma would denote a cancer in which the tumor cells resemble stratified
squamous epithelium
- adenocarcinoma** denotes a *lesion in which the neoplastic epithelial
- cells grow in glandular patterns.*
Sometimes the tissue or organ of origin can be identified, as in
the designation of renal cell adenocarcinoma or bronchogenic squamous cell carcinoma.
Not
infrequently, however, a cancer is composed of undifferentiated cells of unknown tissue origin,
and must be designated merely as an undifferentiated malignant tumor
In many benign and malignant neoplasms, the parenchymal cells bear a close resemblance to
each other, as though all were derived from a single cell. Indeed, neoplasms are of monoclonal
origin, as is documented later.
T or F
T
What are mixed tumors?
Infrequently, divergent differentiation of a single neoplastic clone
along two lineages creates what are calledmixed tumors.
The best example of this is the mixed
tumor of salivary gland origin.
These tumors contain epithelial components scattered within a
myxoid stroma that sometimes contains islands of cartilage or bone
All these
elements, it is believed, arise from a single clone capable of giving rise to epithelial and
myoepithelial cells; thus, the preferred designation of these neoplasms is pleomorphic
adenoma.
What is a pleomorphic adenoma?
Infrequently, divergent differentiation of a single neoplastic clone
along two lineagescreates what are called mixed tumors.
The best example of this is the mixed
tumor of salivary gland origin.
These tumors contain epithelial components scattered within a
myxoid stroma that sometimes contains islands of cartilage or bone
All these
elements, it is believed, arise from a single clone capable of giving rise to epithelial and
myoepithelial cells; thus, the preferred designation of these neoplasms ispleomorphic
adenoma.
The great majority of neoplasms, even mixed tumors, are composed of cells
representative of a single germ layer.
The multifaceted mixed tumors should not be confused
with a teratoma
T or F
T
What is a teratoma?
teratoma, which contains recognizable mature or immature cells or *tissues representative
of more than one germ cell layer and sometimes all three.*
Teratomas originate from totipotential
cells such as those normally present in the ovary and testis and sometimes abnormally present
in sequestered midline embryonic rests.
Such cells have the capacity to differentiate into any of the cell types found in the adult body and so, not surprisingly, may give rise to neoplasms that
mimic, in a helter-skelter fashion, bits of bone, epithelium, muscle, fat, nerve, and other tissues.
When can you say that a teratoma is benign?
When all the component parts are well differentiated, it is a benign (mature) teratoma
When can you say that a teratoma is malignant?
when
less well differentiated, it is an immature, potentially or overtly, malignant teratoma
What is an ovarian cystic teratom (dermoid cyst)
A particularly
common pattern is seen in the ovarian cystic teratoma (dermoid cyst), which differentiates
principally along ectodermal linesto create acystic tumor lined by skin replete with hair,
sebaceous glands, and tooth structures
FIGURE 7-2 This mixed tumor of the parotid gland contains epithelial cells forming ducts
and myxoid stroma that resembles cartilage.
FIGURE 7-3 A, Gross appearance of an opened cystic teratoma of the ovary. Note the
presence of hair, sebaceous material, and tooth. B, A microscopic view of a similar tumor
shows skin, sebaceous glands, fat cells, and a tract of neural tissue (arrow).
What tumors are benign sounding but has been used for certain malignant neoplasms?
For generations, benign-sounding designations such as lymphoma, melanoma, mesothelioma and seminoma have been used for certain malignant neoplasms
misnomer benign tumors
- Hamartomas
- choristoma
What is a hamartoma?
Hamartomas present as disorganized but
benign-appearing masses composed of cells indigenous to the particular site.
They were once
thought to be a developmental malformation, unworthy of the -oma designation.
For example,
pulmonary chondroid harmatoma contains islands of disorganized, but histologically normal
cartilage, bronchi, and vessels.
However, many hamartomas, including pulmonary chondroid
hamartoma, have clonal, recurrent translocations involving genes encoding certain chromatin
proteins. [3] Thus, through molecular biology they have finally earned their -oma designation
What are the two aberrant differentiation( not true neoplasm)?
- hamartoma
- choristoma
What is a choristoma?
Another misnomer is the term choristoma.
This congenital anomaly is better described as a
heterotopic rest of cells.
For example, a small nodule of well-developed and normally organized
pancreatic substance may be found in the submucosa of the stomach, duodenum, or small
intestine.
This heterotopic rest may be replete with islets of Langerhans and exocrine glands.
The term choristoma, connoting a neoplasm, imparts to the heterotopic rest a gravity far
beyond its usual trivial significance
TABLE 7-1 – Nomenclature of Tumors
COMPOSED OF ONE PARENCHYMAL CELL TYPE
- Tumors of Mesenchymal Origin
- Endothelial and Related Tissues
- Blood Cells and Related Cells
- Muscle
- Tumors of Epithelial Origin
- Tumors of Melanocytes
MORE THAN ONE NEOPLASTIC CELL TYPE—MIXED TUMORS, USUALLY DERIVED FROM
ONE GERM CELL LAYER
- Salivary glands
- Renal anlage
MORE THAN ONE NEOPLASTIC CELL TYPE DERIVED FROM MORE THAN ONE GERM CELL
LAYER—TERATOGENOUS
Totipotential cells in gonads or
in embryonic rests
Tumors of Mesenchymal Origin
Connective tissue and
derivatives
BENIGN : MALIGNANT
- Fibroma: Fibrosarcoma
- Lipoma: Liposarcoma
- Chondroma: Chondrosarcoma
- Osteoma : Osteogenic sarcoma
Tumors of Mesenchymal Origin
Endothelial and Related Tissues
TISSUE: BENIGN: MALIGNANT
- Blood vessels:Hemangioma:Angiosarcoma
- Lymph vessels:Lymphangioma:Lymphangiosarcoma
- Synovium :Lymphangioma: Synovial sarcoma
- Mesothelium: Lymphangioma: Mesothelioma
- Brain coverings: Meningioma :Invasive meningioma
Tumors of Mesenchymal Origin
Endothelial and Related Tissues
Tissue: Benign: Malignant
- Hematopoietic cells: NONE :Leukemias
- Lymphoid tissue: NONE :Lymphomas
Tumors of Mesenchymal Origin
Muscle
Tissue : Benign: Malignant
- Smooth :Leiomyoma: Leiomyosarcoma
- Striated : Rhabdomyoma :Rhabdomyosarcoma
Tumors of Mesenchymal Origin
Tumors of Epithelial Origin
Tissue: Benign: Malignant
- Stratified squamous: Squamous cell papilloma: Squamous cell carcinoma
- Basal cells of skin or adnexa :Squamous cell papilloma: Basal cell carcinoma
- Epithelial lining of glands or
ducts : Adenoma: Adenocarcinoma - Epithelial lining of glands or
ducts :Papilloma :Papillary carcinomas - Epithelial lining of glands or
ducts: Cystadenoma : Cystadenocarcinoma - Respiratory passages : Bronchial adenoma : Bronchogenic carcinoma
- Renal epithelium : Renal tubular adenoma :Renal cell carcinoma
- Liver cells : Liver cell adenoma : Hepatocellular carcinoma
- Urinary tract epithelium
(transitional) : Transitional-cell papilloma :Transitional-cell carcinoma - Placental epithelium : Hydatidiform mole :Choriocarcinoma
- Testicular epithelium (germ
cells): NONE :Seminoma ,Embryonal carcinoma
Tumors of Mesenchymal Origin
Tumors of Melanocytes
BENIGN : MALIGNANT
Nevus :Malignant melanoma
MORE THAN ONE NEOPLASTIC CELL TYPE—MIXED TUMORS, USUALLY DERIVED FROM
ONE GERM CELL LAYER
Salivary glands
BENIGN : MALIGNANT
Pleomorphic adenoma (mixed
tumor of salivary origin):
Malignant mixed tumor oF salivary gland origin
MORE THAN ONE NEOPLASTIC CELL TYPE—MIXED TUMORS, USUALLY DERIVED FROM
ONE GERM CELL LAYER
Renal anlage
BENIGN : MALIGNANT
Pleomorphic adenoma (mixed
tumor of salivary origin) : Wilms tumor
MORE THAN ONE NEOPLASTIC CELL TYPE DERIVED FROM MORE THAN ONE GERM CELL
LAYER—TERATOGENOUS
Totipotential cells in gonads or
in embryonic rests
BENIGN: MALIGNANT
Mature teratoma, dermoid cyst :Immature teratoma,
teratocarcinoma
