Familial syndrome and their pathogenesis taht are associated with formation of colon polyps.
Puetz Jeghers are Autosomal Dominant. Multiple hamarotomatous polyps and you get a mucocutanoues pigmentation on the face. Complications: Intusseception (fatal) as well as some malignancies, such as breast, ovarian and other cancers.
Pathogenesis: it is linked iwth LKD1 and STK11 gene which causes it to decrease.
Familial Adenomatous Polyposis (FAP) found on chromosome 5p. THey have multiple polyps throughout the colon. THere are some variants:
Gardner - it is also associated osteomas, retinal hypertrophy, and also there is teeth in the mouth
Turcot - associated with CNS tumors, medulloblastoma, pheoblastoma.
Hereditary NonPolyposis Colon (HNPCC). Also autosomal dominant. Pathogenesis is problem in mismatch repair gene. Associated with MSH2 and MLH1. Increase Short Tandem Randoms.
Colon Cancer Pathogenesis
FAP model and HNPCC mdoel
FAP - mutation in APC then there is two hit. APC generally inhibit B-Catenin which is responsible for activated cyclin D1. Activates mutation of KRas and final hit of p-53
HNPCC model there is mismatch repair which leads to accumulation of gene factor
Risk factors is diet, low Vitamin A, C, K. Tobacco, Smoking, Inflammatory Bowel Disease, Puetz Jeghers, FAP, Villous adenoma for developing colon Cancer
Clinical Findings and Symptoms:
Iron Deficiency Anemia especially in ascending colon, which will be some sort of exophytic mass.
Colicky pain and hematochezia if found in descending colon. Mass will be more infiltrative inwards, not outwards.
Iron Deficiency in elderly, you must rule out Colon cancer
Apple Core lesion on X-ray
CEA as tumor marking