Diseases of large bowel

4th stage

Surgery
Lec-6
Dr.layth

17/4/2016

Rectal tumors
Benign tumour :
Villous adenomas:
These have a characteristic frond-like appearance. They may be very large, and occasionally fill the entire rectum. These tumours have an enhanced tendency to become malignant – a change that can sometimes be detected by palpation with the finger; any hard area should be assumed to be malignant and should be biopsied. Rarely, the profuse mucous discharge from these tumours, which is rich in potassium

Familial adenomatous polyposis

Hyperplastic polyps:
These are small, pinkish, sessile polyps, 2–4 mm in diameter and frequently multiple. They are common and generally harmless.
Inflammatory pseudopolyps
Juvenile polyp

CARCINOMAS :

Types of carcinoma spread :
Local spread:
Local spread occurs circumferentially rather than in a longitudinal direction. After the muscular coat has been penetrated, the growth spreads into the surrounding mesorectum, but is initially limited by the mesorectal fascia.

Lymphatic spread:

Lymphatic spread from a carcinoma of the rectum above the peritoneal reflection occurs almost exclusively in an upward direction.

Venous spread

Peritoneal dissemination

Stages of progression

Dukes classified carcinoma of the rectumTNM staging :
Histological grading:
Low grade, well-differentiated 11 per cent prognosis good;
Average grade, 64 per cent prognosis fair;
High grade, undifferentiated tumours 25 per cent prognosis
poor.


Clinical feature:
Early symptoms of rectal cancer
Bleeding per rectum
Tenesmus
Early morning

Investigations :

Abdominal examination
Rectal examination
Proctosigmoidoscopy
biopsy
Colonoscopy

Treatment :

Surgery

:
Anterior resection
Abdominoperineal resection
Endoluminal stenting
Palliative colostomy

Summary :

Radiotherapy

Chemotherapy
Carcinoid tumour :
Carcinoid tumour originates in the submucosa, with the mucous membrane over it being intact. Consequently, it seldom pro- duces evidence of its presence in the early stages, when it presents as a small plaque-like elevation. The incidence of clini- cal malignancy, i.e. the occurrence of metastases, is 10 per cent.
Further reading 1235
This is much less than that for carcinoid tumour of the small intestine, but it is greater than that for carcinoid tumour of the appendix. Multiple primary carcinoid tumours of the rectum are not infrequent. The neoplasm is of slow progression, and usually metastasises late. Large carcinoids (over 2 cm) are almost always malignant.
Treatment
Local excision is sufficient treatment for small carcinoids. Resection of the rectum is advisable if the growth is more than 2.5 cm in diameter, if recurrence follows local excision or if the growth is fixed to the perirectal tissues. Even when metastases are present, resection may prolong life