Path: senator-bedfellow.mit.edu!bloom-beacon.mit.edu!news.kodak.com!news-pen-14.sprintlink.net!news.sprintlink.net!Sprint!128.122.253.90!newsfeed.nyu.edu!news.idt.net!newsfeed.internetmci.com!206.109.1.106!ultraneo.neosoft.com!uuneo.neosoft.com!scooter-ppp-port-23.neosoft.com!uthman
From: Ed Uthman <
[email protected]>
Newsgroups: sci.med.pathology,sci.med.diseases.cancer,alt.support.cancer,sci.answers,alt.answers,news.answers
Subject: Biopsy Report Guide (monthly posting, 38K, v. 1.2)
Followup-To: poster
Date: 4 Mar 1998 19:45:07 GMT
Organization: Pathanarchy, Inc
Lines: 714
Approved:
[email protected]
Distribution: world
Message-ID: <
[email protected]>
NNTP-Posting-Host: scooter-ppp-port-23.neosoft.com
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
Summary: Explanation of the pathologist's report on biopsies,
aimed at the educated layperson.
X-Newsreader: Nuntius 2.0_PPC
X-XXMessage-ID: <
[email protected]>
X-XXDate: Wed, 4 Mar 1998 19:50:44 GMT
Xref: senator-bedfellow.mit.edu sci.med.pathology:6705 sci.med.diseases.cancer:25062 alt.support.cancer:29602 sci.answers:7922 alt.answers:32555 news.answers:124742
Version: 1.2
Last-modified: November 12, 1997
Archive-name: pathology/biopsy-report-guide
Posting-Frequency: monthly (first Wednesday)
URL:
http://www.neosoft.com/~uthman
Maintainer: Ed Uthman <
[email protected]>
The Biopsy Report: A Patient's Guide
Ed Uthman, MD (
[email protected])
Diplomate, American Board of Pathology
INTRODUCTION
Many medical conditions, including all cases of cancer, must be
diagnosed by removing a sample of tissue from the patient and
sending it to a pathologist for examination. This procedure is
called a biopsy, a Greek-derived word that may be loosely translated
as "view of the living." Any organ in the body can be biopsied using
a variety of techniques, some of which require major surgery (e.g.,
staging splenectomy for Hodgkin's disease), while others do not even
require local anesthesia (e.g., fine needle aspiration biopsy of
thyroid, breast, lung, liver, etc). After the biopsy specimen is
obtained by the doctor, it is sent for examination to another
doctor, the anatomical pathologist, who prepares a written report
with information designed to help the primary doctor manage the
patient's condition properly.
The pathologist is a physician specializing in rendering medical
diagnoses by examination of tissues and fluids removed from the
body. To be a pathologist, a medical graduate (M.D. or D.O.)
undertakes a five-year residency training program, after which he or
she is eligible to take the examination given by the American Board
of Pathology. On successful completion of this exam, the pathologist
is "Board-certified." Almost all American pathologists practicing in
JCAHO-accredited hospitals and in reputable commercial labs are
either Board-certified or Board-eligible (a term that designates
those who have recently completed residency but have not yet passed
the exam). There is no qualitative difference between
M.D.-pathologists and D.O.- pathologists, as both study in the same
residency programs and take the same Board examinations.
TYPES OF BIOPSIES
1. Excisional biopsy. A whole organ or a whole lump is
removed (excised). These are less common now, since the
development of fine needle aspiration (see below). Some types
of tumors (such as lymphoma, a cancer of the lymphocyte blood
cells) have to be examined whole to allow an accurate
diagnosis, so enlarged lymph nodes are good candidates for
excisional biopsies. Some surgeons prefer excisional biopsies
of most breast lumps to ensure the greatest diagnostic
accuracy. Some organs, such as the spleen, are dangerous to
cut into without removing the whole organ, so excisional
biopsies are preferred for these.
A special type of excisional biopsy of the breast is the
needle localization biopsy, also called the "wire-guided
biopsy." This is used when the patient presents with an
abnormal mammogram, but no lump can be felt in the breast.
Since the surgeon cannot feel anything, it is necessary for
the radiologist, who can see the abnormality on the x-ray, to
provide some sort of guide. While the patient is positioned
in the mammography machine, the radiologist (a physician who
specializes in diagnostic imaging) uses the mammogram and a
special grid to insert a needle directly into the abnormal
area. When a follow-up mammogram determines the needle is in
the right place, a wire with a barb on the end is inserted
through the hollow needle into the abnormal area. The needle
is withdrawn from around the wire, leaving the wire fixed in
place (because of the barb, it cannot fall out). The surgeon
then cuts into the breast and follows the wire to the area in
question, removes this area, and sends it to the pathologist.
The pathologist then determines if the appropriate tissue has
been removed and advises the surgeon appropriately. In some
cases, it is necessary to x-ray the actual biopsy specimen to
determine if the suspicious area has been removed.
2. Incisional biopsy. Only a portion of the lump is removed
surgically. This type of biopsy is most commonly used for
tumors of the soft tissues (muscle, fat, connective tissue)
to distinguish benign conditions from malignant soft tissue
tumors, called sarcomas.
3. Endoscopic biopsy.This is probably the most commonly
performed type of biopsy. It is done through a fiberoptic
endoscope the doctor inserts into the gastrointestinal tract
(alimentary tract endoscopy), urinary bladder (cystoscopy),
abdominal cavity (laparoscopy), joint cavity (arthroscopy),
mid-portion of the chest (mediastinoscopy), or trachea and
bronchial system (laryngoscopy and bronchoscopy), either
through a natural body orifice or a small surgical incision.
The endoscopist can directly visualize an abnormal area on
the lining of the organ in question and pinch off tiny bits
of tissue with forceps attached to a long cable that runs
inside the endoscope.
4. Colposcopic biopsy.This is a gynecologic procedure that
typically is used to evaluate a patient who has had an
abnormal Pap smear. The colposcope is actually a close-
focusing telescope that allows the physician to see in detail
abnormal areas on the cervix of the uterus, so that a good
representation of the abnormal area can be removed and sent
to the pathologist.
5. Fine needle aspiration (FNA) biopsy.This is an
extremely simple technique that has been used in Sweden for
decades but has only been developed widely in the US over the
last ten years. A needle no wider than that typically used to
give routine injections (22 to 25 gauge) is inserted into a
lump (tumor), and a few tens to thousands of cells are drawn
up (aspirated) into a syringe. These are smeared on a slide,
stained, and examined under a microscope by the pathologist.
A diagnosis can often be rendered in a few minutes. Tumors of
deep, hard-to-get-to structures (pancreas, lung, and liver,
for instance) are especially good candidates for FNA, as the
only other way to sample them is with major surgery. Such FNA
procedures are typically done by a radiologist under guidance
by ultrasound or computed tomography (CT scan) and require no
anesthesia, not even local anesthesia. Thyroid lumps are also
excellent candidates for FNA.
Because of recent interest in cost containment, FNA is now
widely applied in diagnosing breast lumps. While the
technique is excellent in experienced hands, false negatives
and false positives do occur. A false negative causes delay
in diagnosis of breast cancer allowing the tumor to grow and
spread, and a false positive is likely to result in an
unnecessary mastectomy. I would therefore offer the following
recommendations to any patient who has been encouraged to
have a breast FNA:
Studies have clearly shown that the diagnostic accuracy
of breast FNA is optimal when the same person who
interprets the smears also performs the biopsy itself.
Accordingly, I recommend that patients have the actual
procedure performed by a pathologist who does a good
number of these cases as a part of his or her practice.
FNAs that are positive for cancer should be confirmed
by frozen section at the time of surgery, before the
mastectomy is performed.
An FNA that shows no cancer cells is no assurance that
the patient does not have cancer. A negative FNA means
that either 1) the patient does not have cancer, or 2)
the patient does have cancer, but the needle missed the
diagnostic cells.
6. Stereotactic needle biopsy. This relatively new technique
for evaluating breast lesions attempts to combine the
advantages of FNA (no scar, no anesthesia, inexpensive),
excisional biopsy (acquisition of solid pieces of tissue
rather than smears) and needle localization (precise guidance
by x-ray or ultrasound imaging). The patient lies on her
abdomen, so that the breast hangs down into a space that can
be x-rayed by a computerized imaging device. The computer
displays the mammographic image on a screen. The radiologist
identifies the abnormality and marks it electronically on the
screen. The computer then positions a movable arm directly
over the abnormal area. A biopsy device is attached to the
arm, and the spring-loaded gun quickly inserts a hollow
biopsy needle into the breast. The needle is removed, and the
tissue it contains is sent to the pathologist for diagnosis.
The downside of stereotactic needle biopsy is that, because
only a tiny amount of tissue is removed, a negative result is
no guarantee the patient does not have cancer. Another
problem is that occasionally the biopsy will remove the
portions of the lesion that were responsible for its being
identified as abnormal in the first place. This leaves the
surgeon with no "signpost" to follow in trying to remove by
lumpectomy a cancer that was diagnosed by stereotactic needle
biopsy.
7. Punch biopsy. This technique is typically used by
dermatologists to sample skin rashes and small masses. After
a local anesthetic is injected, a biopsy punch, which is
basically a small (3 or 4 mm in diameter) version of a cookie
cutter, is used to cut out a cylindrical piece of skin. The
hole is typically closed with a suture and heals with minimal
scarring.
8. Bone marrow biopsy. In cases of abnormal blood counts,
such as unexplained anemia, high white cell count, and low
platelet count, it is necessary to examine the cells of the
bone marrow. In adults, the sample is usually taken from the
pelvic bone, typically from the posterior superior iliac
spine. This is the prominence of bone on either side of the
pelvis underlying the "bikini dimples" on the lower
back/upper buttocks. Hematologists do bone marrow biopsies
all the time, but most internists and pathologists and many
family practitioners are also trained to perform this
procedure.
With the patient lying on his/her stomach, the skin over the
biopsy site is deadened with a local anesthetic. The needle
is then inserted deeper to deaden the surface membrane
covering the bone (the periosteum). A larger rigid needle
with a very sharp point is then introduced into the marrow
space. A syringe is attached to the needle and suction is
applied. The marrow cells are then drawn into the syringe.
This suction step is occasionally uncomfortable, since it is
impossible to deaden the inside of the bone. The contents of
the syringe, which to the naked eye looks like blood with
tiny chunks of fat floating around in it, is dropped onto a
glass slide and smeared out. After staining, the cells are
visible to the examining pathologist or hematologist.
This part of procedure, the aspiration, is usually followed
by the core biopsy, in which a slightly larger needle is used
to extract core of bone. The calcium is removed from the bone
to make it soft, the tissue is processed (see "Specimen
Processing," below) and tissue sections are made. Even though
the core biopsy procedure involves a bigger needle, it is
usually less painful than the aspiration.
SPECIMEN PROCESSING
After the specimen is removed from the patient, it is processed in
one or both of two major ways:
1. Histologic sections. This involves preparation of stained,
thin (less than 5 micrometers, or 0.005 millimeters) slices
mounted on a glass slide, under a very thin pane of glass
called a coverslip. There are two major techniques for
preparation of histologic sections:
a. Permanent sections. This technique gives the
best quality of specimen for examination, at the
expense of time. The fresh specimen is immersed in a
fluid called a fixative for several hours (the
necessary time dependent on the size of the specimen).
The fixative, typically formalin (a 10% solution of
formaldehyde gas in buffered water), causes the
proteins in the cells to denature and become hard and
"fixed." Adequate fixation is probably the most
important technical aspect of biopsy processing.
The fixed specimen is then placed in a machine that
automatically goes through an elaborate overnight cycle
that removes all the water from the specimen and
replaces it with paraffin wax. The next morning, a
technical professional, called a histologic technician,
or "histotech," removes the paraffin-impregnated
specimen and "embeds" it in a larger bloc of molten
paraffin. This is allowed to solidify by chilling and
is set in a cutting machine, called a microtome. The
histotech uses the microtome to cut thin sections of
the paraffin block containing the biopsy specimen.
These delicate sections are floated out on a water bath
and picked up on a glass slide.
The the paraffin is dissolved from the tissue on the
slide. With a series of solvents, water is restored to
the sections, and they are stained in a mixture of
dyes. The most common dyes used are hematoxylin, a
natural product of the heartwood of the logwood tree,
Haematoxylon campechianum, which is native to Central
America, and eosin, an artifcial aniline dye. The stain
combination, casually referred to by pathologists as "H
and E" yields pink, orange, and blue sections that make
it easier for us to distinguish different parts of
cells. Typically, the nucleus of cells stains dark
blue, while the cytoplasm stains pink or orange.
b. Frozen sections. This technique allows one to
examine histologic sections within a few minutes of
removing the specimen from the patient, but the price
paid is that the quality of the sections is not nearly
as good as those of the permanent section. Still, a
skilled pathologist and a knowledgeable surgeon can
work together to use the frozen section's rapid
availability to the patient's great benefit.
2. Smears. The specimen is a liquid, or small solid chunks
suspended in liquid. This material is smeared on a microscope
slide and is either allowed to dry in air or is "fixed" by
spraying or immersion in a liquid. The fixed smears are then
stained, coverslipped, and examined under the microscope.
Like the frozen section, smear preparations can be examined within a
few minutes of the time the biopsy was obtained. This is especially
useful in FNA procedures (see above), in which a radiologist is
using ultrasound or CT scan to find the area to be biopsied. He or
she can make one "pass" with the needle and immediately give the
specimen to the pathologist, who can within a few minutes determine
if a diagnostic specimen was obtained. The procedure can be
terminated at that point, sparing the patient the discomfort and
inconvenience of repeated sticks.
PATHOLOGIC EXAMINATION
A. THE GROSS DESCRIPTION
The pathologist begins the examination of the specimen by dictating
a description of the specimen as it looks to the naked eye. This is
the "gross exam" or the "gross." Some pathologists may refer to the
gross exam as the "macroscopic." Most biopsies are small,
nondescript bits of tissue, so the gross description is brief and
serves mostly as a way to code which biopsy came from what area and
to use for troubleshooting if there is a question of specimen
mislabeling. A typical gross description of an endoscopic colon
biopsy follows:
"Polyp of sigmoid colon." An ovoid, smooth- surfaced,
firm, pale tan nodule, measuring 0.6 x 0.4 x 0.3 cm.
Cassette 'A', all, bisected.
In the above example, the first item (in quotes) is an exact
recitation of how the specimen was labeled by the doctor who took
the biopsy. After that is a textual description of what the specimen
looked like, followed by measurements indicating its size. The
"Cassette 'A', all, bisected" phrase indicates that the specimen was
cut in half ("bisected"), submitted for tissue processing in its
entirety ("all") in a small container (cassette) labeled "A," which
will eventually be placed in the tissue processor.
Larger organs removed as biopsies have correspondingly longer and
more detailed gross descriptions. The following is the gross
description of a spleen removed to assess whether Hodgkin's disease
(a cancer of lymph tissues) has spread into it:
"Spleen". An entire spleen, weighing 127 grams, and
measuring 13.0 x 4.1 x 9.2 cm. The external surface is
smooth, leathery, homogeneous, and dark purplish-brown.
There are no defects in the capsule. The blood vessels
of the hilum of the spleen are patent, with no thrombi
or other abnormalities. The hilar soft tissues contain
a single, ovoid, 1.2-cm lymph node with a dark grey cut
surface and no focal lesions
On section of the spleen at 2 to 3 mm intervals, there
are three well-defined pale-grey nodules on the cut
surface, ranging from 0.5 to 1.1 cm in greatest
dimension. The remainder of the cut surface is
homogeneous, dark purple, and firm.
Summary of cassettes: 1, hilar blood vessels; 2, hilar
lymph node, entirely submitted; 3 - 6 spleen nodules,
entirely submitted; 7 - 8, spleen, away from nodules.
In the spleen described above, the pathologist found a few lumps
(nodules), representing the most important data in this gross
examination. These possibly represent the tumors of Hodgkin's
disease, subject to confirmation by the microscopic examination.
Much of the remainder of the verbage relates to "pertinent
negatives," or things that were routinely looked for but not found,
such as a rupture of the spleen capsule (suggesting an
intraoperative accident), blood clots ("thrombi") in the vessels
supplying the spleen, and evidence of an infection (in which case
the cut surface of the spleen would be soft instead of firm). In
addition, a lymph node was serendipitously found adherent to the
spleen, and this was briefly described as having a normal
appearance.
The last paragraph of the gross description gives the identifying
"codes" of the slices of the specimen submitted for microscopic
examination in cassettes. The microscope slides prepared from the
processed samples will be labeled with the same numbers as the
cassettes, and the pathologist doing the microscopic examination
can, by referring to the typed gross description, know from what
part of the specimen the tissue on the slide came.
B. THE MICROSCOPIC EXAMINATION
The microscopic description, or the "micro" is a narrative
description of the findings gained from examination of the glass
slides under the microscope. The micro is considered somewhat
"optional" in a written report. In such a case, the diagnosis (see
below) is considered to speak for itself. Here is a the microscopic
description on the report of the colon biopsy given above:
Specimen A: The sections show a polypoid structure
consisting of a central fibrovascular core, surrounded
by a mantle of mucosa showing an adenomatous
architecture with a predominantly tubular pattern. The
tubules are lined by tall columnar epithelium showing
nuclear pseudostratification, hyperchromasia, increased
mitotic activity, and loss of cytoplasmic mucin. There
in no evidence of stromal invasion.
It can be readily seen that the language of microscopy is much more
arcane than that used for gross descriptions. It is way beyond the
scope of this monograph to cover the nuances of descriptive
microscopic pathology. In general, microscopic descriptions are
communications between pathologists for referral and quality
assurances purposes.
C. THE DIAGNOSIS
This is analogous to the "bottom line" of a financial report. The
purpose of the gross examination, the processing of the tissue, and
the microscopic examination is to build a logical argument toward a
terse assessment of what significance the biopsy has in regard to
the patient's health. Here is the diagnosis for the colon biopsy,
above:
Colon, sigmoid, endoscopic biopsy: tubular adenoma
(adenomatous polyp)
This format is widely used, but variations occur. The first term is
the organ or tissue involved ("colon"). The second term ("sigmoid")
specifies the site in the colon from which the biopsy was obtained.
The next term ("endoscopic biopsy") denotes the type of surgical
procedure used in obtaining the biopsy. Then follows the diagnosis
proper, in this case "tubular adenoma," a common benign tumor of the
large intestine and rectum, which increases the risk for developing
colorectal cancer in the future. In this particular case, an older
synonym for tubular adenoma, "adenomatous polyp," follows in
parentheses.
GLOSSARY OF IMPORTANT DIAGNOSTIC TERMS
Finally, it may be useful to present a brief glossary of important
terms used in pathologic diagnoses. Terms in the definition that are
in ALL CAPS have their own entry.
ABSCESS
A closed pocket containing pus. Some abscesses are easily
diagnosed clinically, as they are painful and may "point out"
such that pus becomes visible, but deep and chronic abscesses
may just look like a TUMOR clinically and require biopsy to
distinguish them from neoplasm.
ATYPICAL
The simple, straightforward definition would be "unusual,"
but "atypical" means much more than that. In a diagnosis, the
use of the term atypical is a vague warning to the physician
that the pathologist is worried about something, but not
worried enough to say that the patient has cancer. For
instance, lymphomas (cancers of the lymph nodes) are
notoriously difficult to diagnose. Some lymph node biopsies
are very disturbing but do not quite fulfil the criteria for
cancer. Such a case may be diagnosed as "atypical lymphoid
HYPERPLASIA." Other important atypical hyperplasias are those
of the breast (atypical ductal hyperplasia and atypical
lobular hyperplasia) and the lining of the uterus (atypical
endometrial hyperplasia). Both of these conditions are
thought to be precursor warning signs that the patient is at
high risk of developing cancer of the respective organ
(breast and uterus).
CARCINOMA
A malignant NEOPLASM whose cells appear to be derived from
EPITHELIUM. This word can be used by itself or as a suffix.
Cancers composed of columnar epithelial cells are often
called adenocarcinomas. Those of squamous cells are called
squamous cell carcinomas. The type of cancer typically
recapitulates the type of epithelium that normally lines the
affected organ. For instance, almost all cancers of the colon
are adenocarcinomas, and columnar epithelium is the normal
lining of the colon. There are exceptions, however.
DYSPLASIA
An ATYPICAL proliferation of cells. This may be loosely
thought of as an intermediate category between HYPERPLASIA
and NEOPLASIA. It finds its best use as a term to describe
the phenomenon in which EPITHELIUM proliferates and develops
the microscopic appearance of neoplastic tissue, but
otherwise tends to "behave itself" and continues to line body
surfaces without actually invading them, as a true malignant
neoplasm would do. It may be convenient (but not totally
accurate) to consider dysplasia as a "pre-cancer" or an
incipient cancer. Probably the most commonly occurring type
of dysplasia is that of the cervix of the uterus, where a
progression from dysplasia to neoplasia can be clearly
demonstrated. Other dysplasias, such as those of the breast
and prostate, are more difficult to clearly relate to
neoplasia at this time.
EPITHELIUM
A specialized type of tissue that normally lines the surfaces
and cavities of the body. There are three main types: 1)
columnar epithelium, which lines the stomach, intestines,
trachea and bronchi, salivary and other glands, pancreas,
gallbladder, nasal cavity and sinuses, uterus (including
inner cervix), Fallopian tubes, kidneys, testes, vasa
deferentia, and other ductal structures, 2) stratified
squamous epithelium, which lines the skin, oral cavity,
throat, esophagus, anus, outer urethra, vagina, and outer
cervix, and 3) transitional epithelium (urothelium), which
lines the urine-collecting part of the kidneys, the ureters,
bladder, and inside part of the urethra.
GRANULOMA
A special type of INFLAMMATION characterized by accumulations
of macrophages, some of which coalesce into "giant cells."
Granulomatous inflammation is especially characteristic of
tuberculosis, some deep fungal infections (like
histoplasmosis and coccidioidomycosis), sarcoidosis (a
disease of unknown cause), and reaction to foreign bodies.
HYPERPLASIA
A proliferation of cells which is not NEOPLASTIC. In some
cases, this may be a result of the body's normal reaction to
an imbalance or other stimulus, while in other cases the
physiologic cause of the proliferation is not apparent. An
example of the former process is the enlargement of lymph
nodes in the neck as a result of reaction to a bacterial
throat infection. The lymphocytes which make up the node
divide and proliferate, taking up more volume in the node and
causing it to expand. An example of hyperplasia in which the
stimulus is not known is benign prostatic hyperplasia (BPH),
in which the prostate gland enlarges in older men for no
known reason. While hyperplasias do not invade other organs
or METASTASIZE to other parts of the body, they can still
cause problems because of their local physical expansion. For
instance, in BPH, the enlarged prostate pinches off the
urethra and interferes with the flow of urine. If untreated,
permanent kidney damage can result.
INFLAMMATION
A reaction, usually mediated by the immune system, to noxious
stimuli, manifested clinically by swelling, pain, tenderness,
redness, heat, and/or loss of function of the affected part.
To a pathologist, however, inflammation means the
infiltration of certain immune system cells into the tissue
or organ being examined. These inflammatory cells include 1)
neutrophils, which are the white blood cells that make up pus
and are seen in acute or early inflammations, 2) lymphocytes,
which are typically seen in more chronic or longstanding
inflammations, and 3) macrophages (histiocytes), which are
also seen in chronic inflammation. Some types of inflammation
are readily diagnosable by the primary care physician, such
as an infected skin wound that is tender, hot, and draining
pus. Other types of inflammation are not so readily apparent
clinically and require biopsy to distinguish them from
neoplasms. The suffix "-itis" is appended to a root word to
indicate "inflammation of _____." For example, cervicitis,
pharyngitis, gastritis, and thyroiditis are inflammations of
the cervix, pharynx (throat), stomach, and thyroid gland,
respectively.
LESION
This is a vague term meaning "the thing that is wrong with
the patient." A lesion may be a TUMOR, an area of
INFLAMMATION, or an invisible biochemical abnormality (like
the abnormality of the sensitivity of the body's cells to
insulin in adult-onset diabetes).
METAPLASIA
The phenomenon by which one type of tissue is replaced by
another type. This often results from chronic irritation of
an EPITHELIAL lining. A good example is the cervix, in which
chronic irritation and INFLAMMATION causes the relatively
delicate normal columnar epithelium to be replaced by tougher
squamous epithelium (similar to that which normally lines the
vagina, which is naturally "built tougher" for obvious
reasons). This phenomenon is called "squamous metaplasia." In
it's pure state, metaplasia is not harmful, but some
metaplasias are markers for increased risk of more serious
diseases. For instance, a type of intestinal metaplasia of
the stomach (in which columnar epithelium of the intestinal
type replaces that of the gastric type) is considered a risk
factor for the subsequent development of cancer of the
stomach.
METASTATIC
Of or pertaining to METASTASIS, or the process by which
malignant NEOPLASMS can shed individual cells, which can
travel through the lymph vessels or blood vessels, lodge in
some distant organ, and grow into tumors in their own right.
There are two major routes of metastasis, 1) hematogenous, in
which the cells travel through the blood vessels, and 2)
lymphogenous, in which the lymphatic vessels conduct the
cancer cells. In the case of lymphogenous metastasis, the
metastatic tumors can grow from cancers cells entrapped in
the lymph nodes that collect the lymph draining from the
organ where the original cancer has developed, causing the
nodes to enlarge. In the case of breast cancer, the axillary
(underarm) nodes are the first to become involved. In the
case of cancer of the larynx (voice box), the nodes on either
side of the neck (cervical nodes) are first. Hematogenous
metastases tend to deposit in the lungs, liver, and brain.
Many cancers metastasize both lymphogenously and
hematogenously. Most cancer operations attempt to remove not
only the cancerous organ, but also the lymph nodes that drain
that organ. Some types of cancer, especially the most common
ones (lung, breast, colon, and prostate cancers) tend to
metastasize to lymph nodes first. Pathologic examination of
these nodes is important in "staging" the cancer, which gives
the patient and the doctor some idea as to the odds of curing
the cancer and how to best treat it. A typical diagnosis of a
specimen of a "radical" removal of a cancer may read like,
Breast, left, mastectomy: infiltrating ductal
cancinoma; three of fifteen axillary nodes
contain metastatic carcinoma.
NECROSIS
Death of tissue. Necrosis may be seen in inflammatory
conditions, as well as in NEOPLASMS.
NEOPLASM, or NEOPLASIA
A "new growth" of the body's own cells, a proliferation of
cells no longer under normal physiologic control. These may
be "benign" or "malignant." Benign neoplasms are typically
tumors (lumps or masses) that, if removed, never bother the
patient again. Even if they are not removed, they are not
capable of destroying adjacent organs or "seeding" out to
other parts of the body. Malignant neoplasms, or "cancers,"
are those whose natural history (i.e., behavior if untreated)
is to cause the death of the patient. Malignancy is expressed
by 1) local invasion, in which the neoplasm extends into
vital organs and interferes with their function, 2)
METASTASIS, in which cells from the tumor seed out to other
parts of the body and then grow into tumors themselves,
and/or 3) paraneoplastic syndromes, in which the neoplasm
secretes metabolic poisons or inappropriately large amounts
of hormones that cause problems with functions of various
body systems.
-OMA
This suffix means "tumor" or "lump." It typically, but not
invariably, refers to a NEOPLASM ("GRANULOMA" is an
exception). In referring to neoplasms, benign ones are
typically referred to by a word, the prefix of which refers
to the organ or tissue of origin, followed by the suffix
"-oma." For example, leiomyoma, osteoma, chondroma, adenoma,
and hemangioma, refer to benign neoplasms of smooth muscle,
bone, cartilage, glandular tissue, and blood vessel tissue,
respectively. The analogous terms for malignant versions of
these neoplasms are, leiomyoSARCOMA, osteosarcoma,
chondrosarcoma, adenoCARCINOMA, and angiosarcoma.There are
exceptions to these vocabulary rules. For instance, hepatomas
and melanomas are all malignant. Other tumors, such as those
of the adrenal glands, cannot be classified into benign or
malignant categories based on pathologic appearance. Only
their behavior in time shows their true colors. An example is
pheochromocytoma (a tumor of the adrenal medulla), ten per
cent of which are malignant, but we don't know just by
looking at the tumor if a given case will fall into that ten
per cent.
POLYP
A structure consisting of a rounded head attached to a
surface by a stalk (also called a "pedicle" or "peduncle"). A
mushroom growing from the soil is an excellent example of
what a polyp looks like. Polyps my be HYPERPLASTIC,
METAPLASTIC, NEOPLASTIC, INFLAMMATORY, or none of the above.
The typical polyps removed from the colon of adults during
colonoscopy are benign neoplasms called tubular adenomas or
adenomatous polyps. The typical nasal polyps that develop in
people with allergies are inflammatory. The common benign
polyps removed from the cervix are of uncertain origin.
SARCOMA
A malignant NEOPLASM whose cells appear to be derived from
those other than EPITHELIUM. The connective tissues of the
body (fibrous tissue, muscle, bone, cartilage, fat, and
lining of joints) tend to give rise to sarcomas. In adults,
CARCINOMAS are much more common than sarcomas. This makes
sense, because as we age, our body linings are assaulted by
one noxious substance after the other. So it is no surprise
that those epithelial cells on the forefront of our battle
with the environment are the first to lose control of their
growth and development. In children, sarcomas make up a
greater proportion of cancers. While the connective tissues
of adults are rather stable and protected from environmental
assault, those of children are still growing and developing,
the cells dividing, raising the likelihood that something
will go haywire and cause a cell to lose control over its
growth.
SUPPURATION, SUPPURATIVE INFLAMMATION
A type of acute INFLAMMATION characterized by infiltration of
neutrophils at the microscopic level and formation of pus at
the gross level. ABSCESS is special type of suppurative
inflammation.
TUMOR
A mass or lump that can be felt with the hand or seen with
the naked eye. This may be a NEOPLASM, HYPERPLASIA,
distention, swelling, or anything that causes a local
increase in volume. The thing to remember is that not all
tumors are cancers, and not all cancers are tumors.
Note: Please send all constructive comments regarding this FAQ to Ed
Uthman, MD (
[email protected]).
This article is provided as is without any express or implied
warranties. While every effort has been taken to ensure the accuracy
of the information, the author assumes no responsibility for errors
or omissions, or for damages resulting from use of the information
herein.
Copyright (c) 1994-96, Edward O. Uthman. This material may be
reformatted and/or freely distributed via online services or other
media, as long as it is not substantively altered. Authors,
educators, and others are welcome to use any ideas presented herein,
but I would ask for acknowledgment in any published work derived
therefrom.
version 1.2U, 11/12/97
