Benign rectal tumor
Rectal polyp1- juvenile polyp
-It is bright red glistening pedunculated sphere
-It occur in infant and children , occasionally persist to adult life
-It has no tendency to malignancy
- patient has bleeding per rectum
- some time prolapsed during defecation , and obstructed and cause pain
Treatment is excision
2- Inflammatory polyp
It is edematous bosses of the mucous membrane and usually associated with colitis
3- Metaplastic polyp
Small, pinkish, sessile, 2-4mm in diameter, multiple , not cause symptom and not malignant
4- Villous adenoma
- it has frond like appearance, large in size , might fill the rectum
- It has tendency to malignant change
- some time it cause profuse mucous discharge containing high potassium which lead to fluid and electrolyte disturbence , hypokalaemai
Treatment excision and biopsy
- recently anew technique to remove the polyps by transanal endoscopic microsurgery TEM.
- All neoplastic polyp can be snared through colonoscope
5-Familial adenomatous polyposis
- it is inhereditory disease, autosomal dominant, the gene of it is isolated on chromosome 5.
- it is either tubular,or tubulovillous, or villous histologically
- It is premalignant, all of them changed to malignancy
Clinical features
- present at age 10-15 years
- patient has diarrhea, bleeding and abdominal pain
Diagnosis;
barium enema, colonoscopy and biopsy
Treatment
- totalproctocolectomy is indicated , either with permanent ileostomy,
or totat proctocolectomy with pouch-anal anastomosis
Carcinoma of the rectum
- incidence ca of colorectum is the second ca.as general.
- in male it is 2nd most common after ca of bronchus it comes
- in female is 4th most common
the rectum is most frequent site involved
- in 5% of cases there is more than one carcinoma present in the rectum or colon (synchronous tumor)
most of carcinoma started as adenoma and it pass to dysplasia then to carcinoma in situ then invasive carcinoma
adenma-carcimnoma siequence
adenom → dysplasia → carcinoma insitu → invasive carcinoma
Risk Factors
1-Aging the incidence rising steadily after age 50 years. More than 90% of cases older than age 50 years
2-Hereditary 80%is sporadic, but20% of patients has family history of colorectal cancer, defects in the APC gene and in mismatch repair genes
3-Environmental and Dietary
- saturated or polyunsaturated fats (animal fat) increases risk of colorectal cancer
- while a diet high in oleic acid (olive oil, coconut oil, fish oil) does not increase risk
- a diet high in vegetable fiber appears to be protective
- obesity and sedentary lifestyle dramatically increase cancer-related mortality
4-Inflammatory Bowel Disease depend on extend and duration of disease
- In ulcerative pancolitis, the risk of carcinoma is approximately 2% after 10 years, 8% after 20 years, and 18% after 30 years.
- Patients with Crohn's pancolitis have similar risk
- screening colonoscopy with multiple random mucosal biopsies has been recommended annually for
a- after 8 years of disease for patients with pancolitis
b- after 12 to 15 years of disease for patients with left-sided colitis
5- smoking , more than 35 years
6- ureterosigmoidostomy
7- Acromegaly
8- Pelvic irradiation
Pathology
A- it is adenocarcinoma arising from the mucosa of the rectum
By cross section it occur as
- an ulcerative
- papilliferous
- infiltrating type
and by histological examination . There is glandular arrangement with sign of malignancy in the cell and it is graded accordingly to
- well- differentiated 11% good prognosis
- averagely differentiate 64% fair prognosis
- anplastic, highly undifferentiated 25% poor prognosis
Colloid carcinoma 12%
either primary or secondary
- the secondary is most common and due to secondary mucoid degeneration of adenocarcinoma, hitologically glandular arrangement preserved and mucous fill the acini
- the primary mucoid , the mucous lies in the cell and displace the nucleus periphery like the the seal of signet ring the prognosis is bad
B- leomyosarcoma smooth muscle tumor (gastrointestinal stromal tumour GIST)
Type of spread of the rectal tumor
1- local spread
-it spread circumferentially rather than longitudinally, it take two year to complete encirclement
- it invade the muscular coat and spread to surrounding mesorectum
- it invade surrounding organ, bladder, prostate, ovary, uterus and later on even sacrum although presacral fascia act as barrier
2- lymphatic spread
- the carcinoma of the rectum above the peritoneal reflection spread to the upward direction to lymph node at superior rectal artery then then to the nodes around inferior mesentric artery
- below the reflection also spread to upward but to the pararectal lymph node and also for the lymph node at internal iliac node
- Downward extension might be occur to the groin could be occur but rare
3-Venous spread
- it is occur at late stage
- anaplastic and rapidly growing tumor in younger patient is more liable to spread by this method
the organ which is the main site for this metastasis is
- liver 34%
- lung 22%
- adrenal 11%
4-Peritoneal dissemination
it occur after penetration of the peritoneal coat, involve peritoneal cavity ,ovary and other organ
staging
Duke staging
1- stage A growth limited to the rectal wall 15% of cases, prognosis is excellent
2- stage B the growth is extend to extrarectal tissue , but not involving free peritoneal surface and no lymph node metastasis, 35% of cases, prognosis is reasonable
3- stage C there is secondary in the regional lymph node 50% of cases
C1 only pararectal lymph node affected
C2 the node accompanying supplying blood vessels are affected
4-Stage D for distal metastasis although not described by Duke
TNM Staging
(T)Definition
Tx Cannot be assessed
T0 No evidence of cancer
Tis Carcinoma in situ
T1 Tumor invades submucosa
T2 Tumor invades muscularis propria
T3 Tumor invades through muscularis propria into subserosa or into nonperitonealized perirectal tissues
T4 Tumor directly invades other organs or tissues or perforates the visceral peritoneum of specimen
Nodal Stage (N)
NX Regional lymph nodes cannot be assessed
N0 No lymph node metastasis
N1 Metastasis to one to three pericolic or perirectal lymph nodes
N2 Metastasis to four or more pericolic or perirectal lymph nodes
N3 Metastasis to any lymph node along a major named vascular trunk
Distant Metastasis (M)
MX Presence of distant metastasis cannot be assessed
M0 No distant metastasis
M1 Distant metastasis present
Clinical feature
1- bleeding it is earliest and most common symptom .often the bleeding is slight in amount and occur at end of defecation or it is noticed as stained cloth
2- alteration of bowel habit it is the most frequent symptom usually diarrhea , there is mucous and or blood with it ( early morning bloody diarrhea),
annular carcinoma cause constipation
3- tenismus and sense of incomplete defecation
4- pain is late stage , in case of intestinal obstruction and also in case of extend of tumor to surrounding organ such as prostate, bladder , sacrum
5- loss of weight in advanced and metastasis
Investagation
1-rectal examination 90% of rectal tumor felt digitally by PR examination
2- abdominal examination
3- proctosigmoidoscopy and biopsy from tumor
4- colonoscopy to exclude the synchronous tumor which occur at5%
5- ultrasound of abdomen to sea metastasis
6- endoscopic ultrasound helpful in staging of tumor
7- ct-scan and MRI abdomen and pelvis
8- Chest x-ray to exclude metastasis
Differential diagnosis
1- adenoma
2-Inflammtory bowel disease
3- amoebic granuloma
4- endometrioma of the rectum
5- carcinoid tumor
6- solitary rectal ulcer
Treatment
treatment is surgery and the aim is
1-is to excise the rectum
2- mesorectum and associated lymph node even in the presence of solitary liver metastasis and lymph node metastasis
In case of locally advanced , preoperative radiotherapy reduce the size and make it more enable for excision
Type of surgery
1- anterior resection
- it is anal sphincter preserving mechanism
- indicated for tumor at upper two third of the rectum in which
- resection of the rectum at least 2cm. below the tumor
- removal of all mesorectum
- high proximal ligation of the inferior mesenteric lymphovascular pedicle
- restoration of continuity by direct end to end anastomosis manually or by stapler
Before the operation you should assess
- fitteen's of the patient for surgery
- stage of tumor
- pre operative preparation of colon
1- bowel preparation by mechanical cleaning using combination of diet and purgative
2- prophylactic antibiotic covering both aerobic and anaerobic organism (cefuroxime and metronidazole) one hour before operation
-laparoscopic anterior resection
2- abdominoperineal resection
- for lower third tumor
- anal sphincter cannot be preserved
- In which the rectum and anal canal removed as one part through abdominal and perineal approach
- end,permnant colostomy at left ilaic fossa area
laparoscopic abdominoperineal resection
3- Hartmann`procedure
- for old patient that can not tolerate long surgery as anterior resection or abdominperineal procedure,- through abdominal approach, excision of the rectum down to within2.5cm. of the anus was done
- and proximal stump was taken as colostomy at left iliac fossa
4-palliative colostomy in case of intestinal obstruction, and later on to do proper surgery if the tumor is resect able
5- more extensive surgery in case of local extension of tumor to bladder, uterus , it is to remove these structure with rectum
6- pelvic exenteration in case more locally extensive tumor , is to remove all pelvic organ with internal iliac and obturator lymph nodes
7-Liver resection
Excision of single or several liver metastasis can be done with low morbidity and mortality
8- local operation for small low grade tumor T1 with in 10 cm. from anal verge ,
recently this done by transanal endoscopic microscopic technique
Radiotherapy
1-adjuvant radiotherapy can reduce local recurrence but long term survival is not affected
2- Pre operative radiation with chemotherapy or with out, reduce the size of tumor and make it `subsequent removal easy
3- palliative irradiation for not operable and recurrent tumor
chemotherapy
- 5-fluorouracil and folinic acid when combined with surgery has significant affect for survival
immunotherapy, monoclonal antibody for disseminated tumor
Prognosis
depend on stage, grade, and centre in which patient treated
50% 5-year survival after surgery
Follow-Up and Surveillance
Patients who have been treated for one colorectal cancer are at risk for the development of recurrent disease (either locally or systemically) or metachronous disease (a second primary tumor).
1-a colonoscopy should be performed within 12 months.
2-CEA often is followed every 2–3 months for 2 years.
Local recurrence
- due to incomplete removal of tumor or implantation of malignant cell during surgery
- only in minority of case recurrent can be removed
Guidelines for Screening
Current American Cancer Society guidelines advocate screening for the average-risk population (asymptomatic, no family history of colorectal carcinoma, no personal history of polyps or colorectal carcinoma, no familial syndrome) beginning at age 50 years.
Recommended procedures include
1-yearly FOBT
2- flexible sigmoidoscopy every 5 years
3- FOBT and flexible sigmoidoscopy in combination
4- air-contrast barium enema every 5 years
5- or colonoscopy every 10 years
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