A mobile mass is found on rectal examination in a 77-year-old male with complaints of blood in his stool. On workup, he is found to have a stage I (Dukes' A), well-differentiated adenocarcinoma. The most appropriate intervention is which of the following?
Answer(s): A
Local treatment of rectal cancer is the treatment of choice in selected individuals with low-lying rectal cancers. The lesion must be mobile, nonulcerated, within 10 cm of the anal verge, less than 3 cm in diameter, less that onefourth the circumference of the rectal wall, and stage T1 or T2 on endorectal ultrasound. Transanal excision is the most straightforward technique of local treatment. It entails full thickness excision of the lesion into the perirectal fat with adequate margins. For early lesions into the submucosa only (T1), no adjuvant therapy is required unless poor prognostic features are present on final pathology (poorly differentiated or lymphatic/vascular invasion). If the lesion penetrates the muscular wall (T2), adjuvant radiation therapy with or without chemotherapy is indicated following surgical removal.Overall, the disease free survival rate is 80%.
A27-year-old female whose father had a colon resection for adenocarcinoma undergoes her first colonoscopy. Over 100 small polyps are seen distributed mainly in her sigmoid and rectum. Multiple polyps are removed and histologic review reveals tubular adenomas with no evidence of atypia or dysplasia. The most appropriate next step in her management is which of the following?
The patient described has familial adenomatous polyposis (FAP). FAP is a rare autosomal dominant inherited form of colorectal cancer that results from a germline mutation in the APC gene. The disease is characterized by the presence of >100 polyps in the large intestine, as well as extraintestinal manifestations such as epidermoid cysts, desmoid tumors, and osteomas. All patients with FAP will develop colorectal cancer if left untreated. The average age of diagnosis is 29 and the average age of the development of cancer is 39. Once diagnosed, the most definitive treatment requires complete removal of the entire colon and rectum in a timely fashion. Surveillance colonoscopy is not protective against the development of cancer regardless of the frequency. The surgical procedure of choice is a proctocolectomy with permanent ileostomy or creation of an ileoanal anastomosis with ileal reservoir such as a J-pouch. Abdominal perineal resection with sigmoid colectomy leaves a significant portion of colon in situ with subsequent risk of developing colon cancer.
Biopsy of a 4-cm sessile polyp of the cecum during a routine screening colonoscopy reveals it to be a villous adenoma with atypia. Attempt at piecemeal snare polypectomy through the colonoscope is unsuccessful. Which of the following is the most appropriate management?
Villous adenoma is a premalignant condition. The incidence of carcinoma in a polyp depends on the histology type and size of the polyp. Tubular adenomas are the most common type of polyps (6080%), but are the least likely to harbor carcinoma (less than 5% if smaller than 1 cm in diameter). Villous adenomas are the least common type, but overall the most likely to contain malignant foci (50% if greater than 2 cm in diameter). In this patient, a formal right hemicolectomy is indicated due to the high probability of finding cancer in the specimen. A lesser operation, such as open or laparoscopic polypectomy, would then require a second operative procedure if cancer is present. Colonoscopic fulguration of such a large lesion carries a high risk for perforation and would not allow histologic examination. Observation with repeat colonoscopy in 1 year is also inappropriate.
A 56-year-old man comes to the hospital. For the past 5 days he has had colicky abdominal pain, vomiting, abdominal distention, and constipation. The most appropriate measure, after IV hydration and nasogastric decompression, in the initial management of this patient is which of the following?
Answer(s): B
This patient presents with classic symptoms of a bowel obstruction. The diagnosis is often made by a thorough history and physical examination. Following the initial evaluation, an acute abdominal x-ray series should be obtained, which includes supine and erect views of the abdomen. The diagnosis is confirmed with the presence of dilated loops of bowel with the presence of air-fluid levels. These plain films may also suggest the location of the obstruction (small vs. large intestine). Abdominal ultrasonography has limited role in the diagnosis or management of intestinal obstruction. Serum electrolyte determination helps in identifying the electrolyte disturbances that have taken place. Fluid loss needs to be corrected with rehydration, and nasogastric suction helps in decreasing abdominal distention. Upper GI endoscopy would increase distention, and is contraindicated. Antiemetics should not be given until a definitive diagnosis is made, and then only if indicated; promotility agents have little to no role in the management of a patient with bowel obstruction, and may even be contraindicated.An annular constricting lesion with overhanging edges is typical of annular carcinoma of the colon. Mechanical small bowel obstruction results in multiple air-fluid levels in distended small bowel loops. Intussusception produces a "corkscrew" appearance on barium enema, and sigmoid volvulus produces a "bird's beak" appearance. In diverticulitis, extravasation of barium outside the lumen of the colon typically is seen.
A 56-year-old man comes to the hospital. For the past 5 days he has had colicky abdominal pain, vomiting, abdominal distention, and constipationHe undergoes barium enema examination. The findings on barium enema, shown in Figure, are most compatible with which of the following diagnoses?
Answer(s): D
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