Disease Information for Adenocarcinoma, rectal: Definition

Colorectal adenocarcinomas can remain clinically silent for years; When present, symptoms often develop insidiously over a period of months and years; The major symptoms suggesting colorectal cancer are rectal bleeding, pain, and a change in bowel habits; Symptoms typically vary depending on where the lesion resides; Neoplasms in the proximal colon, where intestinal contents are relatively liquid, do not generally cause the abdominal pain or change in bowel habits characteristic of obstructive lesions; These lesions often ulcerate and cause chronic blood loss; patients commonly present with complaints of fatigue, palpitations, or even angina pectoris. Physician examination often reveals hemoccult positive stools and laboratory testing demonstrates hypochromic, microcytic anemia characteristic of iron deficiency ;. Thus, the presence of unexplained iron deficiency anemia in any adult male or postmenopausal female patient should prompt a rigorous evaluation for colorectal cancer, that is, endoscopic and/or radiographic visualization of the entire colon; In contrast to right-sided lesions, cancers in the distal colon may bleed, but they often cause constriction of the gut wall and can manifest with abdominal cramping, stool obstruction, or even perforation ; Tumors of the rectosigmoid region may manifest with hematochezia, tenesmus, and narrowing of the caliber of the stool; The differential diagnosis for rectal bleeding should include hemorrhoids, angiodysplasia, diverticulosis, and other benign and malignant tumors ; Clinically apparent metastatic disease may present prior to or after resection of primary colorectal cancer; Symptoms may include pain related to distention of the liver capsule caused by massive hepatomegaly; If disease has spread to the abdomen, both ascites and bowel obstruction may occur; Metastatic spread to the pelvic region may present as bladder dysfunction, sacral or sciatic nerve pain, and vaginal discharge or bleeding; Lesions that have spread to the lung or bone marrow can remain silent until very advanced disease is present---------------------------------[Cecil online 2006]----------------------------------------------

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