Chapter 31 - Colon and Appendix (CHERI NOTES) Flashcards
TRUE OR FALSE.SINGLE CONTRAST BARIUM ENEMA is still occasionally used for the evaluation of colonic obstruction; fistulas and in old; seriously ill or debilitated patients. (p. 780)
TRUE
TRUE OR FALSE.
DOUBLE-CONTRAST (air contrast) barium enema is favored for detection of small lesions (< 1 cm); for documentation of
inflammatory bowel disease and for detailed imaging evaluation of the rectum. (p.780)”
TRUE
___ complements colonoscopy and barium examinations
by demonstrating intramural and extracolonic components of
disease. (p.780)
- it is excellent for demonstrating extrinsic inflammatory
and neoplastic processes that affect the colon:
abscesses; sinuses and fistulas.
CT
- Colonoscopy is sporadically limited by occasional failure
to reach the right colon - then; barium enema or virtual colonoscopy is utilized to
complete the examination.
_____ is more accurate than CT or MR in determining local tumor
extent of rectal carcinomas and is used in the evaluation of other
rectal and perirectal diseases. (p.780)
TRANSRECTAL ULTRASOUND
_____ refers to a radiolucency in a barium pool caused by a
protruding mass lesion. (p.781)
FILLING DEFECT
- on barium enema examinations; filling defects may be POLYPS;
TUMORS; PLAQUES; AIR BUBBLES; FECES; MUCUS or FOREIGN
OBJECTS.
____ are protrusions from the mucosa that produce filling defects
in defects in pools of barium or are etched in white when coated
by barium and outlined by air on double-contrast studies. (p.781)
POLYPS
- may be pedunculated on a stalk or sessile
- they may appearr as “BOWLER HATS” when viewed obliquely
- the term “polyp” is a generic for a protruding lesion and does
not imply a histologic diagnosis.
Air bubbles rise to the highest point of a contrast column
(the “_____ sign”); but fecal material usually remains
dependent. (p.781-782)
CARPENTER’S LEVEL SIGN
- Plaques are flat lesions that barely rise above the mucosal
surface.
_____ is the most common malignancy of the GI tract and the
second most common malignancy in the U.S. (p.782)
COLORECTAL ADENOCARCINOMA
Approximately 50% of Colorectal CA arise in the
___ and __ area. (p.782)
RECTUM and RECTOSIGMOID AREA
- another 25% occur in the sigmoid colon; and
the remaining 25% are evenly distributed
throughout the remainder of the colon. - nearly all cancers of the colon are
adenocarcinomas arising from preexisting
adenomas - most tumors are annular constricting lesions;
2 to 6 cm in diameter; with raised everted edges
and ulcerated mucosa.
TRUE OR FALSE.
Polypoid tumors are less common; some having the
frond-like appearance of villous carcinoma. (p.782)
TRUE
- INFILTRATING SCIRRHOUS TUMORS; so common in gastric CA;
are rare in the large intestine; unless the patient has ulcerative
colitis. (p.782) - the tumor spreads by direct invasion through the bowel wall
into pericolonic fat and adjacent organs; lymphatic channels to
regional nodes and hematogeneously through the portal veins
to the liver and systemic circulation.
TRUE OR FALSE.
In colorectal adenoCA; INTRAPERITONEAL SEEDING from a tumor
that penetrates the colon wall may also occur. (p.782)
TRUE
__ is the most frequent complication of colorectal adenoCA (p.782)
OBSTRUCTION
- other complications are uncommon but include perforation;
instussusception; abscess and fistula formation. - up to 20% of patients have a second tumor of the large bowel
at diagnosis; usually an adenoma or another carcinoma. - approximately 5% of patients will have a second colorectal
CA either simultaneously or subsequently diagnosed.
TRUE OR FALSE.
Patients with ulcerative colitis; Crohn Disease; Familial
adenomatous polyposis syndrome and Peutz-Jeghers syndrome
are at increased risk of colon carcinoma. (p.783)
TRUE
Local disease staging of Colorectal AdenoCA is best evaluated
with ____ or ______. (p.783)
TRANSRECTAL or COLONOSCOPIC
ULTRASOUND
- CT and MR are used for more advanced
disease and to detect recurrence. - microscopic invasion through the bowel wall
andd tumor involvement of normal sized lymph
nodes is not detected by CT or MR.
DIAGNOSIS? (colon) (p.783)
Cross-sectional imaging findings include:
1. Polypoid primary tumor (usually >1 cm)
2. “Apple-core lesions” with bulky; irregular thickening of the
colon wall and irregular narrowing of the lumen.
3. Cystic; necrotic and hemorrhagic areas within the tumor mass;
esp. when the tumor is large.
4. Linear soft tissue stranding into the pericolonic fat often
indicative of tumor extension through the bowel wall
5. Enlarged regional lymph nodes (>1 cm) representing
lymphatic spread of tumor
6. Distant metastases; esp. in the liver.
COLORECTAL ADENOCARCINOMA
- When tumor cause colonic
obstruction;edema or ischemia may thicken
the wall of the uninvolved colon
proximal to the tumor.
4 most common sites of tumor reccurences in COLORECTAL
ADENOCARCINOMA? (p.783)
1. AT THE OPERATIVE SITE; near the bowel anastomosis 2. IN LYMPH NODES that drain the operative site 3. IN THE PERITONEAL CAVITY 4. IN THE LIVER AND DISTANT ORGANS
- The entire abdominal cavity must
be surveyed to detect tumor recurrence - CT; MR and PET-CT are utilized to demonstrate
response to therapy and tumor recurrence
A ____ is defined as a localized mass that projects from the
mucosa into the lumen. (p.783)
POLYP
- because the majority of colorectal cancers are believed to arise from pre-existing adenomatous polyps; the detection of polyps is a major indication for colonosocpy and imaging studies of the colon.
TRUE OR FALSE.
- Polyps less than 5 mm are almost all hyperplastic;
with a risk of malignancy less than 0.5%.
- Polyps 5 to 10 mm in size are 90% adenomas;
with a risk of malignancy of 1% - Polyps 10 to 20 mm in size are 90% adenomas;
with a risk of malignancy of 10% - Polyps larger than 20 mm are 50% malignant
TRUE
_____ polyps are nonneoplastic mucosal proliferation.
They are round and sessile. Nearly all are less than 5 mm in size.
(p.783)
HYPERPLASTIC POLYPS
_____ polyps are distinctly premalignant and a major risk for
development of colorectal carcinoma. (p.783)
ADENOMATOUS POLYPS
- these are neoplasms with a core of connective tissue - approximately 5% to 10% of population older than 40 years have adenomatous polyps
\_\_\_\_\_\_\_ polyps (\_\_\_\_\_\_ polyps) represent 1% of colon polyps. They are a common cause of rectal bleeding in CHILDREN. (p.783)
HAMARTOMATOUS POLYPS
(JUVENILE POLYPS)
- The Peutz-Jeghers polyp is a
type of hamartomatous polyp.
_____ polyps are usually multiple and associated with inflammatory
bowel disease. They account for less than 0.5% of colorectal polyps.
(p.783)
INFLAMMATORY POLYPS
TRUE OR FALSE.
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME is approx.
two-thirds inherited and one-third spontaneous. (p.784)
- Polyps typically carpet the entire colon.
TRUE
- the inheritance pattern is AUTOSOMAL DOMINANT with high penetrance - the polyps are tubulovillous adenomas; which usually are evident by age 20. - Colorectal cancer will eventually develop in nearly all patients; and so; total colectomy with rectal mucosectomy and ileoanal pouch construction is the current recommended therapy.
TRUE OR FALSE.
In FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME
- patients are at risk for numerous extracolonic
manifestation including carcinomas of the small
bowel; thyroid carcinoma; and mesenteric
fibromatosis. (p.784)
TRUE
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME patients with
associated bone and skin abnormalities including cortical
thickening of the ribs and long bones; osteomas of the skull;
supernumerary teeth; exostoses of the mandible; and dermal
fibromas; desmoids; and epidermal inclusion cysts have
been diagnosed as _____ syndrome. (p.784)
GARDNER SYNDROME
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME patients with
associated tumors of the CNS have been grouped as
_____ syndrome. (p.784)
TURCOT SYNDROME
_____ polyps are nonneoplastic growths with a smooth muscle core
covered by mature glandular epithelium. (p.784)
HAMARTOMATOUS POLYPS
- however; patients with the hamartomatous
polyposis syndromes may also
develop adenomatous polyps;
which do carry a risk of malignancy.
TRUE OR FALSE.
PEUTZ-JEGHERS SYNDROME predominantly involves the SMALL BOWEL;
but most cases have gastric and colon polyps as well.
TRUE
- the condition is autosomal dominant with incomplete penetrance. - dark pigmented spots on the skin and the mucosal membranes are characteristic. - risk of carcinoma arising from coexisting adenomatous polyps is 2% to 20% - patients are also at risk for breast CA; uterine and ovarian CA and early age cancer of the pancreas.
_____ is a syndrome of multiple hamartomas including
hamartomatous polyposis of the GI tract; WITH GOITER AND
THYROID ADENOMAS and increased risk of breast cancer
and transitional cell carcinoma of the urinary tract. (p.784)
COWDEN DISEASE
- The syndrome is autosomal dominant and affects mainly Caucasians
- all patients have mucocutaneous lesions with facial papules; oral papillomas and palmoplantar keratoses
_____ syndrome is a disease of OLDER PATIENTS with a
mean age of onset of 60 years. (p.784)
- polyps are distributed througout the stomach; small bowel; and colon.
CRONKHITE-CANADA SYNDROME
- associated skin findings include nail atrophy; brownish skin pigmentation and alopecia.
- patients present with watery diarrhea and protein-losing enteropathy.
TRUE OR FALSE.
LYMPHOID HYPERPLASIA may involve the colon. The normal
lymphoid follicular pattern of diffuse tiny nodules 1 to 3 mm in
diameter with characteristic umbilication is most common in the
TERMINAL ILEUM AND CECUM but may involve any portion of the
colon.
TRUE
- the nodular lymphoid hyperplasia pattern of diffuse nodules larger than 4 mm is associated with allergic; infectious; and inflammatory disorders.
TRUE OR FALSE.
Involvement of the cecum or rectum is most common with
anal and rectal lymphoma increasingly frequent in AIDS patients.
(p.784)
TRUE
- the colon is less commonly involved with lymphoma than the stomach or small bowel. - most are non-hodgkin b-cell lymphoma. - morphologic patterns include small to large nodules that may ulcerate; excavate and perforate and diffuse infiltration of the bowel wall resulting in bulbous folds and thickened bowel wall.
TRUE OR FALSE.
LYMPHOMA NODULES vary in size although LYMPHOID HYPERPLASIA
NODULES are uniform in size. (p.785)
TRUE
- the diffuse multinodular form may be
difficult to differentiate from nodular
lymphoid hyperplasia.
TRUE OR FALSE.
(In colonic lymphoma); as in the small intestine; marked
narrowing of the lumen is uncommon; aneurysmal
dilation occurs when transmural disease destroys innervation.
TRUE
____ account for nearly all mesenchymal tumors of the colon.
p.785
GI stromal tumors (GISTs)
- true colonic leiomyomas and leiomyosarcomas are very rare - GISTs are much less common in the colon than in the stomach and small bowel accounting for only 7% of the total. - as in the remainder of the GI tract they may appear as exophytic; mural or intramural masses. - ulceration is relatively frequent. - hemorrhagic; cystic change; necrosis and calcifications are more common in larger tumors.
____ is the most common submucosal tumor of the colon. (p.785)
LIPOMA
- barium studies demonstrate a smooth; well-defined elliptical filling defect; usually 1 to 3 cm in diameter. - the tumors are soft and change shape with compression. - CT demonstration of a fat density tumor is definitive.
2 most frequent locations of the colonic lipomas. (p.785)
CECUM and ASCENDING COLON
- nearly 40% present with intussusception
TRUE OR FALSE.
EXTRINSIC MASSES commonly cause mass effect on the colon
that may simulate intrinsic disease. (p.785)
TRUE
TRUE OR FALSE.
ENDOMETRIOSIS commonly implants on the sigmoid colon and
the rectum. (p.785)
TRUE
- defects are frequently multiple
and of variable size. - lesions are commonly within
the cul-de-sac
* barium studies demonstrate sharply defined defects that compress but do not usually encircle the lumen. * CT demonstrates complex cystic pelvic masses with high- density fluid components. Multiple pelvic organs may be incorporated into the mass. * MR demonstrates masses with signal characteristics of hemorrhage.
______ such as ovarian cysts ; cystadenomas; teratomas; and
uterine fibroids produce smooth extrinsic mass impressions of the
colonic wall. The colon is displaced but not invaded. (p.785)
BENIGN PELVIC MASSES
MALIGNANT PELVIC TUMORS and METASTASES may involve the
colon by these 3 ways. (p.785)
- the involved colon demonstrates thickening of the wall;
separation of folds; spiculation; angulations; narrowing and
serosal plaques.
1. BY CONTIGUOUS SPREAD; spread along mesenteric fascial planes 2. BY INTRAPERITONEAL SEEDING; through lymphatic channels 3. BY EMBOLUS through blood vessels.
- metastases oten cannot be
differentiated from primary
tumors by imaging methods
TRUE OR FALSE.
Crohn disease and metastatic disease may also look exactly
alike radiographically. (p.785)
TRUE
-CT or MR demonstrates contiguous involvement
of the colon and the rectum by pelvic tumors.
______ is an uncommon idiopathic inflammatory disease
involving primarily the mucosa and submucosa of the colon.
ULCERATIVE COLITIS
- the peak for its appearance is 20 to 40 years;
but onset of disease after age 50 is common. - the disease consists of superficial ulcerations;
edema and hyperemia.
4 Radiographic hallmarks of Ulcerative Colitis. (p.785-786)
- Granular mucosa
- Confluent shallow ulcerations
- Symmetry of disease around
the lumen - Continuous confluent diffuse
involvement
- an early fine; granular pattern is produced by mucosal hyperemia and edema that precedes ulceration. - superficial ulcers spread to cover the entire mucosal surface - the mucosa is stippled with barium adhering to the superficial ulcers.
____ ulcers are deeper ulcerations of thickened edematous
mucosa with crypt abscesses extending into the submucosa. (p.786)
COLLAR BUTTON ULCERS
- A coarse granular pattern is produced later by the replacement of diffusely ulcerated mucosa with granulation tissue. - late changes include a variety of polypoid lesions.
____polyps are mucosal remnants in areas of extensive ulceration.
(p.786)
PSEUDOPOLYPS
____ polyps are small islands of inflamed mucosa. (p.786)
INFLAMMATORY POLYPS
____ polyps are mucosal tags that are seen in the quiescent
phases of the disease (ulcerative colitis). (p.786)
POSTINFLAMMATORY POLYPS
___ polyps are postinflammatory polyps with a characteristic
worm-like appearance. (p.786)
FILIFORM POLYPS
- typically seen in an otherwise
normal appearing colon
____ polyps may occur during healing after mucosal injury. (p.786)
- involvement typically extends from the rectum proximally in
a symmetric and continuous pattern. (p.786)
HYPERPLASTIC POLYPS
- the terminal ileum is nearly always
normal in ulcerative colitis
Rare ______ may produce an ulcerated but
patulous terminal ileum. (p.786)
BACKWASH ILEITIS
DIAGNOSIS? (COLON) (p.786) CT findings include: 1. wall thickening; often with "halo sign" of low-density submucosal edema 2. Narrowing of the lumen of the colon 3. Pseudopolyps and pneumatosis coli with megacolon.
ULCERATIVE COLITIS
4 complications of Ulcerative Colitis (p.786)
1. Strictures; usually 2 to 3 cm or more in length and commonly involving the transverse colon and the rectum 2. Colorectal AdenoCA; with an approximate risk of 1% per year of disease 3. Toxic megacolon (2% to 5% of cases) may be the initial manifestation 4. Massive hemorrhage
TRUE OR FALSE.
Associated extraintestinal diseases of Ulcerative Colitis include:
Sacroilitis mimicking ankylosing spondylitis (20% of cases); eye lesions
including uveitis and iritis (10% of cases); cholangitis and an increased
incidence of thromboembolic disease. (p.786)
TRUE
This disease condition involves the colon in 2/3rds of all cases and is
isolated to the colon in approximately 1/3 of all cases.
- its hallmarks include early aphthous ulcers; later confluent
deep ulcerations; predominant right colon disease; discontinuous
involvement with intervening regions of normal bowel;
assymetric involvement of the bowel wall; strictures; fistulas and
sinus formation. (p.786)
CROHN DISEASE
- pseudodiverticula of the colon are formed by asymmetric fibrosis on one side of the lumen; causing saccular outpouches on the other side. - involvement of the rectum is characterized by deep rectal ulcers and multiple fistulous tracts to the skin.
TRUE OR FALSE.
INFECTIOUS COLITIS may be caused by various bacteria (Salmonella; Shigella; and Escherichia coli); parasites; viruses (CMV and herpes); and fungi (histoplasmosis and mucormycosis). (p.787)
TRUE
- most cause a pancolitis with edema and inflammatory wall thickening with infiltration of pericolonic fat. - pericolonic fluid and intraperitoneal fluid may be present
______ is a potentially fatal condition characterized by marked
colonic distension and risk of perforation. (p.787)
TOXIC MEGACOLON
- it occurs as a complication of fulminant colitis often caused by ulcerative colitis; Crohn disease; pseudomembranous colitis; use of anti-diarrheal drugs and hypokalemia. - transmural inflammation causes large areas of denuded mucosa; deep ulcers that may extend to the serosa surface and loss of muscle tone.
DIAGNOSIS? (COLON) (p.787)
Radiographic findings include:
1. Marked dilatation of the colon (transverse colon > 6 cm)
with absence of haustral markings
2. edema and thickening of the colon wall
3. pneumatosis coli
4. evidence of perforation
TOXIC MEGACOLON
TRUE OR FALSE.
Barium studies should be avoided in TOXIC MEGACOLON
avoided because of risk of perforation. (p.787)
TRUE
_____ is an inflammatory disease of the colon; and occasionally;
the small bowel; characterized by the presence of a
pseudomembrane of necrotic debris and overgrowth of Clostridium
difficile. (p.787)
PSEUDOMEMBRANOUS COLITIS
- there are many contributing causes including antibiotics (any that change bowel flora); intestinal ischemia (especially following surgery); irradiation; long-term steroids; shock and colonic obstruction. - the disease presents as fulminant inflammatory bowel disease with diarrhea and foul stools
DIAGNOSIS? (COLON) (p.788) Conventional radiographs may reveal: 1. Dilated colon 2. Nodular thickening of the haustra 3. Ascites
TOXIC MEGACOLON
- BARIUM ENEMA demonstrates an irregular lumen with thumbprint indentations similar to ischemic colitis. - superficial ulcers are common - plaque-like defects on the mucosal surface are due to the pseudomembranes - the colitis is frequently patchy in distribution with sparing of the rectum.
DIAGNOSIS? (COLON) (p.788)
This condition is commonly first detected on CT; which shows:
1. marked wall thickening up to 30 mm (average 15 mm) with halo
or target appearance
2. ACCORDION SIGN
- characteristic stripes of intraluminal contrast media trapped
between nodular areas of wall thickening
3. Mild pericolonic fat inflammation disproportionate with the marked
colonic wall inflammation
4. Ascites
TOXIC MEGACOLON
____ is an infection by the protozoan parasite Entamoeba histolytica.
(p.788)
AMEBIASIS
- the disease is worldwide but particularly
common in South Africa; Central and South
America and Asia - Encysted amebae are ingested with
contaminated food and water - the cyst capsule is dissolved in the small
bowel; releasing trophozoites that migrate
to the colon and burrow into the mucosa;
forming small abscesses. - the infection can spread throughout the
body by hematogenous embolization or
direct invasion.
The ___ and ___ are the primary sites of colonic disease in
amebic colitis. (p.788)
CECUM and RECTUM
- the terminal ileum is characteristically
not involved.
____ produces dystentery with frequent bloody mucoid stools.
Barium studies demonstrate a disease that closely mimics
Crohn colitis with aphthous ulcers; deep ulcers; asymmetric
disease and skip area. (p.788)
AMEBIC COLITIS
TRUE OR FALSE. (p.788)
Complications of Amebiasis include:
1. Strictures
2. Amebomas consisting of a hard fixed mass of granulation tissue
that may simulate carcinoma
3. Toxic megalcolon
4. Fistulas; particularly following surgical intervention.
TRUE
- AMEBIC LIVER ABSCESS results from the spread of infection through the portal system and may be complicated by diaphragm perforation; pleural effusion and thoracic disease.
____ is a potentially fatal infection of the cecum and the ascending
colon usually seen in patients who are neutropenic and immuno-
compromised by chemotherapy. (p.788)
TYPHLITIS
(NEUTROPENIC COLITIS)
- concentric; often marked; thickening of the wall of the cecum and the ascending colon with prominent pericolonic inflammatory changes are characteristic. - patients are at risk for colon ischemia
TRUE OR FALSE. (p.788)
ISCHEMIA COLITIS mimics ulcerative colitis and Crohn colitis
both clinically and radiographically.
TRUE
- causes include arterial occlusion caused by arteriosclerosis; vasculitis or arterial emboli; venous thrombosis due to neoplasm; oral contraceptives and other hypercoagulable conditions and low flow states such as hypotension; congestive heart failure and cardiac arrhythmias.
In ISCHEMIC COLITIS (p.789);
The pattern of involvement generally follows the distribution of a
major artery and is the clue to diagnosis.
The ____ artery supplies the right colon from the cecum to the
splenic flexure.
The ____ artery supplies the left colon from the splenic flexure
to the rectum.
SUPERIOR MESENTERIC ARTERY;
INFERIOR MESENTERIC ARTERY
The ____ and ____ are watershed areas most susceptible to
ischemic colitis. (p.789)
SPLENIC FLEXURE REGION;
DESCENDING COLON
- early changes include thickening of
the colon wall; spasm and spiculation.
In ISCHEMIC COLITIS (p.789);
As blood and edema accumulate within the
bowel wall; multiple nodular defects are
produced in a pattern called “_____”.
THUMBPRINTING
- progression of the disease
results in ulcerations; perforation;
scarring and stricture.
TRUE OR FALSE. (p.789) In ISCHEMIC COLITIS; CT demonstrates symmetrical or lobulated thickening of the bowel wall with an irregular narrowed lumen.
TRUE
- TARGET SIGN: submucosal edema may produce a low-density ring bordering on the lumen - Air in the abnormal bowel wall (pneumatosis) is highly suggestive of ischemia. - thrombus may occasionally be demonstrated within the superior mesenteric artery or vein.
AIDS-associated colitis occurs most commonly in AIDS patients with
CD4 lymphocyte counts below ____. (p.789)
below 200
- Causative organisms are most commonly
CMV or cryptosporidiosis;
although the HIV itself may cause ulceration
and colitis. - right colon disease is most common with
wall thickening and ulceration.
TRUE OR FALSE.
RADIATION COLITIS may be indistinguishable radiographically
from early ulcerative colitis. (p.789)
TRUE
- the diagnosis is made by confirmation
of the involved colon being within an
irradiation field.
The ___ region is most commonly involved
(RADIATION COLITIS) due to radiation
of pelvic malignancy. (p.789)
RECTOSIGMOID REGION
- colitis is produced by a slowly progressive
endarteritis that causes ischemia and fibrosis. - radiographic findings include thickened
folds; spiculation; ulceration; stricture;
and occasionally fistula formation - fibrosis results in a rigid; featureless bowel.
- healing may include formation of
pseudopolyps and postinflammatory polyps
____ colon is due to chronic irritation of the mucosa by laxatives
including castor oil; bisacoldyl and senna. (p.789)
CATHARTIC COLON
- the involved colon may be dilated and without
haustra; or narrowed - the RIGHT COLON is most commonl affected
- bizarre contractions are often observed
- the diagnosis is made by clinical history
____ colitis is increasingly common especially in
immunocompromised patients. (p.789)
Imaging findings mimic Crohn disease:
1. marked thickening of the wall of the colon and
terminal ileum
2. markedly enlarged lymph nodes; often with low
central attenuation or calcification.
3. common fistulas and sinus tracts
4. colitis may be segmental or diffuse
5. short strictures may mimic colon cancer
6. thickening of the peritoneum and extensive
abdominal adenopathy suggest the disease.
TUBERCULOUS COLITIS
______ is a cause of abdominal pain that may mimic appendicitis;
diverticulitis and colitis. (p.789)
EPIPLOIC APPENDAGITIS
- caused by ischemic infarction of epiploic appendages; often resulting from torsion. - patient present with focal abdominal pain; tenderness and low-grade fever.
_____ are pedunculated fatty structures that occur in rows on the
external aspect of the colon adjacent to the anterior and posterior
taenia coli.
EPIPLOIC APPENDAGES
- they occur in greatest concentration
in the cecum and the sigmoid colon
sparing the rectum
DIAGNOSIS? (colon) (p.789)
diagnosis is usually made by CT showing:
1. 1 to 4 cm ovoid mass with central fat density
and surrounding inflammation abutting the
wall of the colon
2. Hyperdense enhancing rim surround the
mass (“RING SIGN”).
3. Inflammatory changes may extend into the
adjacent peritoneum.
4. a central high-attenuation dot is often
present representing the central thrombosed
vessels
5. infracted tissue may eventually calcify.
EPIPLOIC APPENDAGITIS
_____ is an acquired condition in which the mucosa and the
muscularis mucosae herniate through the muscularis propria of the
colon wall; producing a saccular outpouching. (p.789)
COLON DIVERTICULOSIS
- colon diverticula are classified as false diverticula because the sacs lack all the elements of the normal colon wall. - the condition is rare under age 25; but increases with age thereafter to affect 50% of the population over age 75. - the major risk factor for diverticulosis is a low-residue die ; typical of Western countries. - the condition is very uncommon in cultures where a high-residue diet is the norm; such as African native populations.
TRUE OR FALSE.
The formation of diverticular sacs is usually associated with
thickening of the muscularis propria; including both the circular
muscle and the taenia coli. (p.790)
TRUE
- severely affected portion of bowel are usually shortened in length; resulting in crowding of the thickened circular muscle bundles. - muscle dysfunction associated with diverticulosis may result in pain and tenderness without evidence of inflammation - diverticulosis without diverticulitis is a cause of painless colonic bleeding that may be brisk and life-threatening.
DIAGNOSIS? (colon) (p.790)
CONVENTIONAL ABDOMINAL RADIOGRAPHS demonstrate
gas-filled sac parallel ot the lumen of the colon.
BARIUM STUDIES show diverticula as barium or gas-filled sacs
outside the colon lumen.
COLON DIVERTICULOSIS
- sacs vary in size from tiny spikes to 2 cm in diameter. - most are 5 to 10 mm in diameter. - they may occur anywhere in the colon but are most common and usually most mumerous in the sigmoid colon. - some sacs are reducible and may disappear with complete filling of the lumen - others may contain fecal residue. -the associated muscle abnormality is seen as thickening and crowding of the circular muscle bands with spasm and spiked irregular outline of the lumen.
TRUE OR FALSE. In colon diverticulosis; (p.790) CT demonstrates the muscle hypertrophy as a thickened colon wall and distorted luminal contour. The diverticula are shown as well-defined gas-;fluid- or contrast-filled sacs outside the lumen.
TRUE
____ is inflammation of diverticula; usually with perforation and
intramural or localized pericolic abscess. (p.790)
ACUTE DIVERTICULITIS
- diverticulitis eventually complicates approximately 20% of the cases of diverticulosis. - clinical signs include painful mass; localized peritoneal inflammation; fever and leukocytosis.
TRUE OR FALSE. (p.790)
Complications of diverticulitis include bowel obstruction; bleeding;
peritonitis; and sinus tract and fistula formation.
TRUE
- Diverticulitis is a less common cause of colon obstruction than is colon carcinoma. - obstruction due to diverticulitis is often temporarily relieved by smooth muscle relaxants such as glucagon
TRUE OR FALSE. (p.790)
- Colon bleeding is more often associated with
diverticulosis than diverticulitis.
TRUE
TRUE OR FALSE. (p.790)
Most diverticular abscesses are quickly walled off and confined;
but free perforation with pus and air in the peritoneal cavity and
diffuse peritonitis may occur.
TRUE
- sinus tracts may lead to larger abscess cavities in the peritoneal or retroperitoneal compartments - fistulas are most common to the bladder; vagina or skin; but may develop to any lower abdominal organ including fallopian tubes; small bowel and other parts of the colon.
TRUE OR FALSE (p.790)
Diverticulitis of the right colon may be mistaken clinically for
acute appendicitis.
TRUE
- Diverticulitis is efficiently diagnosed
radiographically by barium enema or CT. - barium enema examination is considered
safe except when signs of free intraperitoneal
perforation or sepsis are present.
DIAGNOSIS? (colon) (p.790)
Hallmarks of this condition on barium enema include:
1. deformed diverticular sacs
2. demonstration of abscess
3. extravasation of barium outside the colon lumen
ACUTE DIVERTICULITIS
- the smooth outline of the involved sacs is deformed by inflammation and perforation - the resulting abscess cause extrinsic mass effect on the adjacent colon - the colon lumen is narrowed but tapers at the margins of narrowing in distinction with the abrupt narrowing of carcinoma
In ACUTE DIVERTICULITIS (p.790)
Barium leaks into the abscess cavities or forms tracks paralleling
the colon lumen and often connecting multiple perforated sacs
(“ ____ ____ sign”).
DOUBLE TRACK SIGN
- CT excels at demonstrating the paracolic inflammation and abscess associated with diverticulitis as well as complications such as colovesical fistula.
DIAGNOSIS? (colon) (p.790) CT findings are: 1. localized wall thickening 2. inflammation of pericolonic fat 3. pericolonic abscess 4. diverticula at or near the site of inflammation 5. common involvement of the adnexa with fluid collections and fistulas
ACUTE DIVERTICULITIS
____ imaging studies are often selected as the screening
examination of choice for confirming the presence of; and often
localizing; lower GI bleeding. (p.790-791)
RADIONUCLIDE
imaging studies
Technetium-99m-sulfur colloid or Technetium-99m-red blood cell
studies are capable of detecting bleeding at rates
below _____ mL/min. (p.791)
bleeding at rates BELOW 0.1 mL/min
- a negative scintigraphic study usually
precludes the need for urgent angiography
Angiography requires bleeding rates of ___ mL/min or greater.
(p.791)
0.5 mL/min or greater
- however; angiography is more specific than
scintigraphy in demonstrating the anatomic
cause of bleeding and offers the
possibility of nonoperative treatment by
by embolization.
TRUE OR FALSE. (in lower GI hemorrhage) (p.791)
Colonoscopy is usually unrewarding because of the
large quantities of sticky; melanotic stool.
Barium enema is not used to evaluate acute
hemorrhage because it usually cannot locate
the source of bleeding and it will interfere with any
subsequently needed angiographic procedure.
TRUE
- CT angiography performed with IV contrast
and without intraluminal contrast shows
promise in the detection of hemorrhage by
documenting intraluminal extravasation of
intravenously administered contrast. - CT angiography also provides etiological
and anatomic detail. - This information is useful to the
interventional radiologist or surgeon
as they may be able to identify the culprit
mesenteric vessel or assess the conditiion
of the femoral arteries before attempted
therapy
____ refers to ectasia and kinking of mucosal and submucosal
veins of the colon wall. (p.791)
ANGIODYSPLASIA
- the condition results from a chronic intermittent obstruction of the veins where they penetrate the circular muscle layer. - a maze of distorted; dilated vascular channels replaces the normal mucosal structures and is separated from the bowel lumen only by a layer of epithelium. - Angiography demonstrates a tangle of ectatic vessels without an associated mass
TRUE OR FALSE.
Angiodysplasia is acquired and probably related to aging.
The average age of affected patients is 65 years.
TRUE
The appendix arises from the ____ aspect of the cecum at the
junction of the taenia coli; approx. _____ cm below the ileocecal
valve.
POSTEROMEDIAL aspect;
1 to 2 cm below the ileocecal valve
The appendix is a blind-ended tube that is ____ mm in diameter and
approx.___ cm in length; although it may be up to 30 cm long. (p.791)
4 to 5mm in diameter;
approx. 8 cm in length
- its mucosa is heavily infiltrated with lymphoid tissue. - the appendix is quite variable in position: it may be pelvic; retrocecal or retrocolic; and intraperitoneal or extraperitoneal in location.
The appendix always arises from the cecum on the ___ side as the
ileocecal valve. (p.791)
SAME SIDE
- a posterior position of the ileocecal valve
indicates a posterior position of the appendix - on CT; US and MR; the normal appendix appears
as a thin-walled tube less than 6 mm in diameter.
_____ is the most common cause of acute abdomen. (p.792)
ACUTE APPENDICITIS
- the most difficult patients are women of childbearing age; in whom ruptured ovarian cysts and pelvic inflammatory disease may mimic acute appendicitis. - results from obstruction of the appendiceal lumen - continued mucosal secretions cause dilation and increased intraluminal pressure that impairs venous drainage and results in mucosal ulceration - bacterial infection causes gangrene and perforation with abscess.
TRUE OR FALSE. (p.792)
Most periappendiceal abscesses are walled off; but free
perforation and pneumoperitoneum occasionally occur.
TRUE
TRUE OR FALSE (p.792)
Conventional films demonstrate an appendiceal calculus
(appendicolith or fecalith) in approximately 14% of patients
with acute appendicitis.
TRUE
- an appendicolith is formed by calcium deposition around a nidus of inspissated feces. - the resultant calcification is usually laminated with a radiolucent center. - appendiceal abscess or periappendiceal inflammation may result in a visible soft tissue mass in the right lower quadrant. - the lumen of the cecum; as outlined by gas; will be deformed; localized ileus may be evident.
TRUE OR FALSE.
In acute appendicitis; (p.792)
Barium enema examination is frequently NONSPECIFIC.
Complete filling of the appendix to its bulbous tip is strong
evidence AGAINST appendicitis.
TRUE
- However; nonfilling of the appendix; as would be expected with luminal obstruction; has no diagnostic value of its own. - mass impression on the cecum has many causes besides appendicitis.
TRUE OR FALSE.
US; using the graded compression technique; is quite accurate in
providing a definitive diagnosis and is commonly the imaging
technique of choice in women of childbearing age and in children.
TRUE.
Slow grade compression is applied
with a near focus transducer
to the area of maximum
tenderness.
The normal appendix has a diameter of less than __ mm
when compressed. (p.792)
less than 6 mm
4 US signs of Acute Appendicitis. (p.792)
1. Non-compressible appendix larger than 6 mm in diameter; measured outer wall to outer wall 2. visualization fo a shadowing appendicolith 3. inflamed periappendiceal fat becomes more echogenic and fixed moving with the appendix during compression 4. color doppler shows increased vascularity in the wall of the appendix.
- with perforation; sonography demonstrates a loculated pericecal fluid collection; a discontinuous wall of the appendix and prominent pericecal fat. - When the US examination is negative for appendicitis; an alternate diagnosis; such as hemorrhagic ovarian cyst; can frequently be suggested based on visualized abnormalities.
___ is the imaging method of choice (acute appendicitis) in men;
in older patients; and when periappendiceal abscess is suspected.
(p.792)
CT
Definitive CT diagnosis of acute appendicitis is based on these
three findings. (p.792)
1. An abnormally dilated (> 6 mm) appendix 2. Enhancing appendix surrounded by inflammatory stranding or abscess 3. Pericecal abscess or inflammatory mass with a calcified appendicolith
- an INFLAMMATORY MASS is seen as indurated soft tissue mass with a CT density greater than 20 H - a liquefied mass less than 20H in CT density is evidence of ABSCESS - Abscesses larger than 3 cm generally require surgical or catheter drainage - Smaller abscesses commonly resolve on antibiotic treatment alone.
TRUE OR FALSE. (p.792)
MR competes with US as the diagnostic method of choice for
appendicitis in pregnant women and in children.
TRUE
Findings are similar to CT: 1. Dilated appendix larger than 6 to 7 mm diameter 2. Periappendiceal inflammation seen as high signal intensity on fat-suppressed T2WI 3. Thickened wall of the appendix 4. Appendicolith seen as focal area of low signal intensity in the lumen of the appendix 5. Periappendiceal phlegmon or fluid collection high in signal intensity in T2WI.
______ refers to distension of all or a portion of the appendix
with sterile mucus. (p.793)
- the lumen is obstructed by appendicolith; foreign body;
adhesions; or tumor
- some cases are due to mucinous cystadenomas or
cystadenocarcinomas of the appendix.
MUCOCELE
- Continued secretion of mucus produces
a large (up to 15 cm); well-defined cystic
mass in the right lower quadrant. - appendiceal dilatation greater than 13 mm
suggests possible mucocele. - Peripheral calcification may be present.
Rupture of the mucocele (in appendix)
may result in ____. (p.793)
PSEUDOMYXOMA PERITONEI
- gelatinous implants spread throughout
the peritoneal cavity; causing adhesions
and mucinous ascites.
________ is the most common tumor of the appendix; accounting
for 85% of all tumors. (p.793)
CARCINOID
The _____ is the most common location for carcinoid tumor;
accounting for 60% of all carcinoids. (p.793)
APPENDIX
- most occur near the tip and are round; nodular tumors up to 2.5 cm in size. - most are solitary and have less tendency to metastasize than carcinoids elsewhere in the GI Tract. - Carcinoid syndrome is rare; and the mesenteric reaction seen with small bowel carcinoid is usually absent
TRUE OR FALSE.
ADENOMAS occur in the appendix usually in association
with familial multiple polyposis. (p.793)
TRUE
- Isolated adenomas are usually
mucinous cystadenomas associated
with mucocele of the appendix
TRUE OR FALSE.
ADENOCARCINOMA of the appendix is rare and is
usually discovered in the clinical setting of suspected appendicitis
in an older adult. (p.793)
TRUE
Imaging demonstrates a soft tissue
mass within or replacing the
appendix.
