10.03.2017

1. INVESTIGATIONS
SANJUKTA SAHA
10.03.2017
Malda Medical College

2. SCREENING AND CONFIRMATION OF DIAGNOSIS
DETECTION OF METASTASIS AND SPREAD
PROGNOSIS

3. Preliminary Investigations
 Digital Rectal Examination
 Laboratory studies:
• Complete Blood Count, Hematocrit, PCV,
ESR - Anemia
• Liver Function Test
• Renal function test
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4. Fecal Occult Blood Test
• Simple, Non invasive.
• Detects peroxidase in hemoglobin
• Not specific for location of bleeding in the GIT
• Types:
 Guaiac based FOBT
 Immunochemical based FOBT
• False positive results- diet containing red meat
• Combined with flexible Sigmoidoscopy
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5. COLONOSCOPY
• Investigation of choice
• Bowel preparation and sedation required
• Picks up primary cancer
• Can detect synchronous polyps and multiple
carcinomas
• Detects small polyp (<1cm)
• Uses: THERAPEUTIC DIAGNOSTIC
Polypectomy
Control Bleeding
Stricture dilatation
Biopsy

6. • Risk of Perforation
• Contraindications:
 Suspected Colonic perforation
 Toxic megacolon
 Fulminant Colitis
 Severe IBD with ulceration
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7. RADIOLOGY
DOUBLE CONTRAST BARIUM ENEMA
• Constant irregular filling defect
• False positive – 1-2%
• False negative 7-9%
• Detects polyps > 1 cm
• More accurate in proximal colon
• Disadvantage : Misinterpret polyp for
diverticular disease
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8. CT Colonography
• Virtual Colonoscopy
• Noninvasive technique that visualizes the entire
colon
• Categorization of Lesions:
C0 : Study inadequate
C1 : Study Normal
C2 : Indeterminate (Polyp 6-9mm, <3 in no.)
C3 : >10 mm or >3 in 6-9 mm
C4 : Colonic mass with luminal narrowing or
extra-colonic extension

9. • Risk of perforation
• Disadvantage over
conventional
colonoscopy:
 Radiation
exposure
 Intersystem
variability
 Biopsy cannot
be taken
CT colonography shows a large
polypoid adenocarcinoma in the
cecum adjacent to the ileocecal valve.
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10. METASTASIS AND SPREAD
1. ULTRASONOGRAPHY SPREAD TO LIVER (>1.5 cm)
PERITONEUM, LYMPH NODES,
RETROVESICAL SECONDARIES
2. CT SCAN
CT Angiography
• ASSESS LOCAL SPREAD, INVASION,
EXTENT, STAGE, LYMPH NODE
INVOLVEMENT
• LIVER METASTASIS
• LUNG METASTASIS
3. FNAC SUPRACLAVICULAR LYMPH NODES
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11. Ultrasound scan through the right
lobe of the liver showing large
hyperechoic metastasis from colon
cancer.
Ultrasound scan of a large cecal
carcinoma showing concentric
thickening of the hypoechoic bowel
wall by the tumor.
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12. Contrast-enhanced CT showing liver
metastases. Several low-density
metastases from the colon primary
tumor involve both lobes of the liver.
CT scan in patient with rectal carcinoma
and liver metastases, showing
pulmonary metastasis in right lower
lobe.
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13. Surveillance
• CT Surveillance of Chest, Abdomen, Pelvis
• Frequent clinical evaluation
• CEA testing
• Follow-up colonoscopy
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14. Prognosis - CEA
• Tumor marker discovered by Gold and Freedman
• Surface glycoprotein produced by colonic epithelium
• t ½ = 10 days
• Normal level <2.5ng/ml
• >5ng/ml is significant
• Low sensitivity
MALIGNANT BENIGN
COLORECTAL CARCINOMA
PANCREATIC CARCINOMA
GASTRIC CARCINOMA
LUNG CARCINOMA
BREAST CARCINOMA
PANCREATITIS
HEPATITIS
OBSTRUCTIVE JAUNDICE
BPH

15. IMPORTANCE OF CEA AS A
PROGNOSTIC MARKER
1. Pre operative level > 7.5 ng/dl – Poor prognosis
2. Post operative fall not adequate – metastasis or
incomplete resection
3. During follow up, increased CEA – recurrence or
secondaries
4. Rapid increase in CEA levels – metastasis
5. For follow up, post-op CEA levels checked 3
monthly for first 2 years even if pre op level was
normal
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16. TNM Staging
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