This document summarizes colorectal carcinoma, including risk factors, pathology, spread, staging, clinical features, diagnosis, differential diagnosis, and treatment options. It notes that colorectal carcinoma is the fourth most common cancer in females and second most common in males after lung cancer. Risk factors include advanced age, diet high in animal fat, genetic factors, and conditions like familial adenomatous polyposis or inflammatory bowel disease. Diagnosis involves examinations like sigmoidoscopy, colonoscopy, or barium enema to detect tumors. Treatment depends on tumor location and staging but may include surgery such as anterior resection or abdominoperineal resection with or without radiation, as well as palliative procedures.

1. Carcinoma
colorectal carcinoma is the fourth most common
variety of malignant tumour found in female and
2nd in male after ca. lung risk factors;
advanced age, dilatory factors ( high animal fat),
genetic factors , F.A.P ,, U/COLITIS,, crohn with
colorectal involvements, family history ofca. Colon.
pathology; 3 types a- well differentiated
adenocarcinoma .b- averagely differentiated
adenocarcinoma c- anaplastic highly
undifferentiated adenocarcinoma.
Macroscopically; ulcerative --papilliforous—
infilrating--annullar

2. Spread of tumour;
Local ; it occur circumferentially rather than longitudinally
,period of 6 months is required for involvement of quarter
of the circumference and 18-24 months to complete
encirclement.
If spread occur anteriorly the prostate, seminal vesicles or
bladder involve in male.in female vagina or uterus is
invaded.
If spread lateral may involve ureter
If posterior involve sacrum and sacral plexus
Lymphatic spread;
Enlargement of l.n from bacterial infection more common
than infiltration by malignant cells.

3. Direction of lymphatic spread usually up
word except 1-2cm near the anal orifice
If neoplasm lie within the field of middle
rectal artery (4-8 cm from the anus)spread
goes laterally accompany middle rectal vein
Groin lymph node may involve if spread
goes subcutaneously.

4. Venous spread
Its usually occur late except when the tumor is highly
malignant and occur in young patients spread occur early
.liver involve 34% lung 22% adrenal 11%
Peritoneal dissemination;
may occur in high lying rectal carcinoma.
Dukes staging;
Stage a the growth is limited to the rectal wall 15% prognosis
excellent
Stage b the growth is extended to the extrarectal tissue but
no metastasis to the regional lymph node 35% prognosis
reasonable
Stage c regional l.n involved 50% it divided to C1—local
pararectal l.n alone are involve C2 ---- l.n accompanying
the supplying blood vessels are involved

5. Stage d wide spread metastasis usually liver
Tnm --
T – tumor local spread T1.T2.T3.T4
N nodal involvement N1,,N2,,N3
M distal metastasis M0,,M1
Histological grading
Low grade = well differentiated 11% good
prognosis
Average grade= 64%
prognosis fair
High grade = anaplastic tumor 25% poor
prognosis

6. Clinical feature
The patient may present with the following:
1- BLEEDING is the earliest and most common symptoms ,
usually bleeding is slight and after deification. 2- sense of
incomplete defecation its very important early symptoms
and its almost invariably present in tumour of lower half of
the rectum.
3- alteration of bowel habit usually early morning bloody
diarrhea
4- pain which is the late symptoms but colicky abdominal
pain due to some degree of intestinal obstruction because
of advanced growth in rectosegmoidal area.

7. Examination
Abdominal palpation is negative in early
cases, but careful attention must be paid to
the detection of hepatomegaly, ascites or
abdominal distension. Other general
features that may be detected in late cases
are enlarged supraclavicular nodes, nodes in
the groin or jaundice. Rectal examination
reveals the tumour in 90% of cases.

8. Special investigation
- Sigmoidoscopy enables the great majority of
tumours to be inspected and a biopsy to be taken
-Colonoscopy ;is required if possible in all patients to
exclude a synchronous tumour be it
COLONOSCOPY; entire colon and distal small
bowel
FLEXIBLE SIGMOIDOSCOPY; distal 60 cm
RIGID PROCTOSCOPY Distal 25 cm

9. - Barium enema is indicated when colonoscopy
cannt do it or if the growth is not visualized
sigmoidoscopically or colonoscopically,or if a
second tumour is suspected (5% of tumours in the
large bowel are multiple) or if there is ulcerative
colitis or familiar polyposis.
- Ultrasound of the abdomen may detect liver
metastases and/or ascites. While transrectal u/s
for determine the depth of rectal –wall invasion by
small tumours and lymph node involvement.
C.T SCAN & MRI and segmdooscopy for detacting
local recurance

10. Differential diagnosis of a rectal tumour
Differential diagnosis of a palpable tumour in the rectum
must be made from the following:
- benign tumours inflammatory stricture solitary ulcer
- secondary deposits in the pelvis
- ovarian or uterine tumours
- extension from carcinoma of the prostate or cervix
- diverticular disease
- endometriosis
- lymphogranuloma inguinale
- amoebic granuloma
- faeces (these give the classical physical sign of indentation).

11. Treatment
Curative
Surgery depends upon the distance of the tumour from the
anal verge.
Upper-third tumours can be resected with restorative
anastomosis between the sigmoid colon and the lower
rectum (anterior attention).
Lower-third tumours less than 5 cm from the anal verge, are
usually treated by abdominoperianal excision of the
rectum, with a terminal colostomy.
Adjunctive radiotherapy may reduce the incidence of local
recurrence after abdominoperianal resection.
Mid-third rectal tumours can usually be treated by anterior
resection, provided satisfactory
distal clearance can be obtained. The operation is easier in
women, where the wider pelvis facilitates dissection.

12. Preoperative preparation
1-mechanical bowel preparation
2-counselling and sitting of stomas
3-correction of anemia and electrolyte
4- cross-matching of blood
5- Prophylactic antibiotic
6-deep vein thrombosis prophylaxis
7- insertion of urethral catheter.

13. Palliative procedures
 Even if secondary's are present, palliation is the
best achieved when possible by excision of the
primary tumours. A colostomy may be necessary
for intestinal obstruction, but this does not relieve
the bleeding, mucus discharge and sacral pain.
 In completely inoperable cases, deep x-ray therapy,
diathermy or laser of the tumour may give
temporary relief, as may cytotoxic drugs.

14. Carcinoid tumour of the rectum;
 Its originate from submucosa of the rectum .the mucouse
membrane over it intact ,some time appear as a small
plaque like elevation ,its less common than carcinoid
tumour of small intestine and greater than that of append
ix ,multiple primary carcinoid tumour of rectum are not
infrequent. Its of slow progression and usually late
metastasis. Large carcinoid more than 2 cm its almost
always malignant. This tumor usually metastasis to the
bone and frequently a symptomatic ,but if it secreat
serotonin about 66% of patients become complaining from
effect of serotonin such as diarrhea why diarrhea ?( it cause
increase bowel tone , motility, fluid secreation and blood
flow .

15. Treatment
 Local excision is sufficient treatment
.resection of rectum is advisable if a-the
growth is more than 2,5 cm in diameter b-
recurrence fallow local excision c-the
growth is fixed to the perirectal tissues.