1. Case 124: A 45 y/o man with Occult Blood in his Stool

2. History
This 45 year-old male veteran was admitted to the Omaha Veterans Administration Hospital for workup of a positive occult blood test. This patient tested his own stool with an occult blood test supplied by Methodist Hospital and WOWT (television station). The hospital informed him that the test was positive and he should seek medical attention. Past medical history revealed mild chronic bronchitis and mild hypertension currently being treated with propranolol. The patient received a recent cholecystectomy.
Family history; a brother (age 47) had colon cancer, their father died at age 60 of colon cancer, and one of the father’s sisters had endometrial carcinoma.

3. P. E.
a well-developed, well-nourished male in no acute distress. BP 140/90, P.= 80/min, Resp 16/min.
HEENT: within normal limits, neck was supple and no bruit heard
Chest: occasional rhonchi noted, otherwise auscultation and percussion unremarkable
Heart: regular rhythm at 80/min - no murmurs
Abdominal exam: no masses or tenderness on palpation
Bowel sounds: normal, active
Rectal exam: an enlarged but non-tender nodular prostate, but no rectal lesions felt
Stool occult blood test: positive

4. Write a problem list and differential
Write a problem list and differential. What tests and/or procedures would your order at this time?

5. Labs: CBC: Hgb: - 11.3 gm/dL MCV: - 72 FL WBC: - 8.0 x 103/ L
Diff.: - unremarkable
Platelets: 240,000 mm3
Urinalysis: - unremarkable
Chemistry:
Electrolytes Na: 140 mmol/L,
K: mmol/L,
Cl: 100mmol/L,
CO2 (HCO2): 22 mmol/L
BUN mg/dL
Creatinine - 1 mg/dL
Glucose - 90 mg/dL

6. Discuss the implications of finding occult blood in the stool
Discuss the implications of finding occult blood in the stool. (Discuss in terms of age groups, gender, and possible causes.) Explain the hematology findings.
Outline the workup of a positive stool occult blood test. (Look this up!)
What would you do next?

7. Additional Lab Results
Serum Fe micrograms/dL

8. The patient had a flexible colonoscopic examination of the entire colon and a large sessile villous lesion was noted in the ascending colon. Biopsies showed a “villous adenoma; however, the presence of invasive carcinoma could not be ruled out.” The patient subsequently underwent a segmental resection of the right colon which revealed a large villous adenoma with a small ulcer in the center. Visual examination of the abdominal cavity showed no evidence of neoplastic disease.

9. Role of colonoscopy and biopsy

10. Surgical resection specimen- segment of large bowel- large villous adenoma( looks like a ‘shaggy rug’). Ulcer in center may be from biopsy

11. Cut section of villous adenoma
Cut section of villous adenoma. Looks like a wart-- grossly it does not invade into the muscularis

12. Normal colon: Note the normal mucosa with muscularis mucosa.

13. Another look at normal colon. Note distribution of goblet cells
Another look at normal colon. Note distribution of goblet cells. Note that the nuclei are generally at the base of the cells.

14. Comparison of normal mucosa and adenomatous epithelium
Comparison of normal mucosa and adenomatous epithelium. Note loss of goblet cells and general darkness at base of the cells - this represents enlargement of nuclei and increased DNA in the neoplastic cells. These are not malignant yet--there is still good basement membrane around the glands and there is no evidence of invasion through the muscularis mucosa
Normal adenomatous

15. The majority of the lesion, a villous adenoma as shown in this photomicrograph

16. Scanning power photomicrograph
Scanning power photomicrograph. Note the neoplastic glands in the submucosa, undermining the villous adenoma.

17. A area of invasive carcinoma deep in the muscular wall: note irregular gland formation

18. High power photomicrograph of the neoplasm.

19. What is a polyp. A villous adenoma. A flat adenoma
What is a polyp? A villous adenoma? A flat adenoma? And what are their relationship to colon carcinoma?
Describe the gross morphologic patterns of carcinoma of the colon and symptoms and signs associated with each.

20. Another villous adenoma

21. Classic ‘applecore’ lesion of the left colon
Gross specimen showing a common manifestation of adenocarcinoma of the colon. This is a constricting "napkin ring" lesion. This is more common in the descending and sigmoid colon. This lesion may or may not bleed.

22. Fungating lesion (classic for right colon)
Example of a small ulcerated adenocarcinoma. This is the type of lesion that typically presents with positive fecal occult blood test.

23. Grade and stage is this man's tumor in the modified Dukes (Astler-Coller) and TNM system? How does the grade relate to the stages?

24. Diagrammatic view demonstrating the modified Dukes staging system

25. What is the five-year survival rate
What is the five-year survival rate? Or how would you explain his survival to him and his family (be specific – patients don’t want generalities – look this up on the web – your patient has!)

27. Comparison of AJCC, Dukes, and Astler-Coller Stages
AJCC/TNM
Dukes
Astler-Coller
5 year survival I A
A, B1
93%
IIA B B2
85%
IIB B3
72%
IIIA C C1
83%
IIIB
C2, C3
64%
IIIC
C1, C2, C3
44% IV D 8%

28. Chart with the prognosis according to modified Dukes(Astler/Coller) stage in 1954 (compare to today)

29. What risk factors are associated with colon carcinoma?
Outline the work up of a positive stool occult blood test.
Describe the histologic and cytologic criteria of malignancy? What is anaplasia?
What is the role of carcinoembryonic antigen (CEA) test in the diagnosis and management of colon carcinoma.
What is the significance of the positive family history? What is the molecular and genetic basis for this type of colon cancer?