Transcript DIFFERENTIAL DIAGNOSIS

ADENOCARCINOMA
•
mutation of APC (adenomatous polyposis gene).
The protein encoded by APC is important in activation of oncogene c-myc
and cyclin D1, which drives the progression to malignant phenotype.
• abnormal DNA methylation
can cause silencing of tumor suppressor genes or activation of oncogenes,
compromising the genetic balance and ultimately leading to malignant
transformation.
• Other important genes
KRAS oncogene , chromosome 18 loss of heterozygosity (LOH) leading to
inactivation of SMAD4 (DPC4), and DCC (deleted in colon cancer) tumor
suppression genes.
Chromosome arm 17p deletion and mutations affecting p53 tumor
suppressor gene confer resistance to programmed cell death (apoptosis) and are
thought to be late events in colon carcinogenesis.
ADENOCARCINOMA
•Hematochezia or blood-streaked stool
•Change in bowel habits (severe constipation
due to obstruction)
•Abdominal discomfort or pain due to mass
•Narrow stools
•Feeling of unfinished bowel movement
•Weight loss due to cachexia
• Annular lesions
– irregular, circumferential masses that
severely constrict the bowel lumen
– margins of the carcinoma show overhanging
edges, the tumor shelf or shoulder (termed
"APPLE-CORE or NAPKIN RING" lesion).
– mucosal folds in the narrowed segment are
destroyed; ulceration may be present
LATERAL VIEW: Prominent
Apple Core Deformity and
Irregular Mucosa
DIFFERENTIAL DIAGNOSIS:
INFLAMMATORY BOWEL DISEASE
• an idiopathic disease, probably involving an
immune reaction of the body to its own
intestinal tract.
• The 2 major types of IBD are ulcerative colitis
and crohn’s disease
INFLAMMATORY BOWEL DISEASE
• The pathophysiology is under active investigation.
•
The common end pathway is inflammation of the mucosal lining
of the intestinal tract, causing ulceration, edema, bleeding, and
fluid and electrolyte loss.
• Possible factors related to this event include:
1. pathogenic organism (as yet unidentified)
2. immune response to an intraluminal antigen
3. an autoimmune process
ULCERATIVE COLITIS
Clinical Manifestations:
Blood streaked stool
Abdominal pain or cramps
Urgency and tenesmus
Weight loss in severe cases
Extracolonic manifestations
Radiologic Findings
– Continuous lesion
– lead pipe appearance of the
colon because of the loss of
normal haustral markings.
– granular mucosal pattern
CROHN’S DISEASE
• involve any segment of the gastrointestinal tract from the
mouth to the anus.
Manifestations include the ff:
• Diarrhea due to malabsoprtion, and abdominal pain
• Fever due to infection
• fatigability due to anemia
• weight loss
• blood streaked stool in colonic involvement
• May also present with intestinal obstruction ie borborygmi,
abdominal distention
• bloating, crampy pain
CROHN’S DISEASE
• discontinuous (skip)
lesions
• Aphthae appear as 1 to 2
mm barium-filled craters
surrounded by a lucent
halo
enlarge, they
coalesce forming a lattice
work of confluent ulcers
resulting in the so called
"COBBLESTONE"
appearance
COLON DIVERTICULITIS
• inflammation of one or more diverticula
• pathogenesis :
-Fecal material/undigested food particles may collect in a
diverticulum
obstruction
distension of the
diverticula
Vascular compromise
microperforation
/macroperforation then ensue.
COLON DIVERTICULITIS
Clinical Manifestations:
Abdominal pain,
hematochezia
Fever, leukocytosis, nausea,
vomiting, flatulence, palpable
masses, muscle guarding, and
partial obstruction
constipation, diarrhea, and
bloating
• Soft-tissue densities
suggestive of abscesses
• Narrowing, deformity, or
displacement of the bowel
lumen