D01.1

Clinical Causes: Accumulation of genetic mutations in the cells lining the rectosigmoid junction Chronic inflammation or inflammatory bowel disease Diet high in processed and red meats, low in fiber Lifestyle factors such as smoking and excessive alcohol consumption Genetic predispositions and family history of colorectal cancers Previous radiation therapy in the pelvic area

Key Symptoms: Changes in bowel habits, such as diarrhea or constipation Rectal bleeding or blood in stool Persistent abdominal discomfort or cramps Unexplained weight loss Feeling of incomplete bowel evacuation No symptoms in early stages; often detected during screening procedures

Diagnosis Path: Colonoscopy: A flexible tube with a camera is used to visually examine the rectum and sigmoid colon, allowing for direct observation and biopsy of suspicious areas. Biopsy: Small tissue samples obtained during colonoscopy are examined microscopically to identify abnormal cell growth characteristic of carcinoma in situ. Imaging tests: Techniques such as CT scans or MRI may be used to assess the extent of abnormality and rule out invasion beyond the mucosal layer. Fecal tests: Stool tests may suggest bleeding, prompting further investigation. Histopathological analysis: Microscopic evaluation of tissue samples confirms the diagnosis.

Treatment Protocols: Endoscopic resection: During colonoscopy, abnormal tissue can often be removed using techniques like polypectomy or mucosal resection. Surveillance: Regular follow-up colonoscopies are essential to monitor for recurrence or progression. Lifestyle modifications: Dietary changes, smoking cessation, and alcohol moderation may reduce risk factors. Surgical intervention: In cases where lesion removal is incomplete or suspicion of invasion arises, surgery to remove part of the rectum or sigmoid colon might be recommended. Adjuvant therapy: Typically not required at the in situ stage, but may be considered if invasive features are identified.