2. » LARGE INTESTINES ˃APPENDIX ˃ASCENDING COLON ˃TRANSVERSE COLON ˃DESCENDING COLON ˃SIGMOID

6. » Peritoneum- ˃Upper third covered anteriorly and laterally ˃Middle covered only anteriorly ˃Lower none ˃Forms rectovesical and rectouterine space as reflects anteriorly

9. » Superior Rectal » Middle Rectal » Inferior Rectal » Anastomosis

10. » Parallels arteries » Dual Drainage » Superior rectal drains into portal » Middle/Inf. –drain into systemic

11. » Starts at anorectal junction and end at anal verge » Anal columns consist of longitudinal folds » Superior border is anorectal line which divides the rectum and anus » Inferior border is the dentate line » Dentate line divides columnar above and squamous below » Sup. Rectal supplies the anus above the dentate

12. » Innervation above dentate is same as the rectum –only sensitive to stretch » Below the dentate the inferior rectal of the pudendal supplies the anus- pain touch temperature

13. » Abnormal growth of mucosa » Pedunculated-stalk » Sessile-flat » Nonneoplastic polyps: Hyperplastic Inflamatory-regenerating epithelium Juvenile<10 years –hamartomas-distal colon

14. » Series of molecular changes » Mutation in k-ras on chromosome 12 p is found in 65% of sporadic colon ca » Deletions in APC gene (5q –tumor supressor gene)

15. COLORECTAL POLYPS Table 46-1. CLASSIFICATION OF COLORECTAL POLYPS MUCOSAL POLYPS NeoplasticBENIGN Adenomatous polyps (dysplastic mucosa) TubularTubulovillousVillous MALIGNANT Carcinoma in situ Invasive carcinoma Polypoid carcinoma Nonneoplastic Hyperplastic polyps Juvenile polyps Peutz-Jeghers polyps Inflammatory polyps Normal epithelium SUBMUCOSAL POLYPS LipomasLeiomyomas Colitis cystica profunda Pneumatosis cystoides intestinalis Lymphoid aggregates Lymphoma (primary or secondary) Carcinoids Metastatic neoplasms

19. » FAP- thousand of polyps deletion APC gene (5q) IAA » Colon ca at mean age of 35 » Gardener’s –variant of FAP –osteomas, lipomas and sarcomas » Turcot’s –brain tumors » Variable manifestations of mutation in same gene

20. » Lynch syndrome » Autosomal dominant » Mutation on chromosome 2 » Other cancers endometrial stomach and urinary tract

21. » Peutz-Jeghers –hamartomas polyps associated with cutaneous pigmented lesions » Low risk of malignancy » Cowden’s DZ hamartomas with facial epithelial lesions-increased risk for breast cancer » Cronkhite Canada –hamartomas, alopecia diarrheas and hyerpigmentation

26. » Radiation for rectal cancer » Generally recommended for pts with stage II dz » Colon ca-chemo for stage II/III » 5-FU/LV

28. » Squamous cell cancer » Bowen dz carcinoma in situ » Chemo /RT » Nigro Protocol » Excellent sphincter preservation