12. A, Film from an enteroclysis demonstrating a smooth,
submucosal lesion that was found to be lipoma (arrow). B,
Surgical resection specimen of a lipoma from another
patient who presented with intussusception and bleeding
13. CT scan of the lower abdomen demonstrates a soft tissue mass of fat density in the
lumen of the terminal ileum (arrow). These characteristics are diagnostic for a lipoma
14. Small bowel follow through examination demonstrates a smooth, well-circumscribed mass
arising from the wall of the terminal ileum. The appearance is consistent with a benign
mesenchymal tumor, such as a lipoma or a carcinoid tumor
15. Small bowel follow through examination shows a polypoid eccentric mass
arising from the wall of the terminal ileum (arrow).
16.
17.
18. Small bowel follow through examination demonstrates a circumferential apple- core
lesion of the jejunum (arrow), producing distension of the proximal small bowel.
20. Film from a small bowel follow through demonstrating an “apple-core” appearance caused by
a metastatic lesion to the small intestine from a scirrhous gastric cancer.
21. Upper gastrointestinal endoscopy shows a duodenal adenocarcinoma in the second
portion of the duodenum in a patient who presented with heme positive stool. The mass
occupied approximately 50 percent of the diameter of the duodenum. The thick
erythematous folds in the upper half of the image distinguish the lesion from the pale,
thin folds of the normal tissue in the lower half.
22. Contrast examination of the small intestine in a patient with partial small bowel
obstruction and extensive extramucosal disease caused by metastatic lung cancer.
23. Small bowel follow through study shows multiple rounded, nodular filling defects in the
wall of the small bowel (arrows). Multiple small bowel tumors may be seen in metastatic
disease or in polyposis syndromes; the most common cause of small bowel metastases is
melanoma.
25. Involvement of the intestine by a
lymphoid malignancy extending from
involved retroperitoneal or mesenteric
lymph nodes
26.
27.
28.
29. Barium enema shows a large soft tissue mass in the cecum (arrows)
caused by intussusception of a lymphoma arising in the terminal
ileum
30. CT scan of the abdomen demonstrates a large mass in the lumen of a distended loop
of small bowel. Note mesenteric fat in the center of this intraluminal mass (arrow).
31.
32.
33. The use of oral antibiotics such as
tetracycline appears to be beneficial in
the early phases of the disorder,
suggesting a possible infectious
etiology.
Combination chemotherapy has been
administered during later stages of the
disease, with variable results
34. Carcinoid tumors arise from argentaffin cells of
the crypts of Lieberkühn and are found from the
distal duodenum to the ascending colon, areas
embryologically derived from the midgut. More
than 50% of intestinal carcinoids are found in the
distal ileum, with most congregating close to the
ileocecal valve. Most intestinal carcinoids are
asymptomatic and of low malignant potential,
but invasion and metastases may occur, leading
to the carcinoid syndrome
36. CT scan demonstrates a soft tissue mass containing coarse central calcifications (short arrow)
in the right lower quadrant. This carcinoid tumor is producing a characteristic desmoplastic
response with spiculation of the adjacent mesenteric fat (long arrow).
37.
38. Capsule endoscopy view of an ulcerated mass in a patient who presented with
gastrointestinal bleeding. Four ulcerated, bleeding masses were found throughout the
small bowel; these were confirmed at surgery and found to be sarcomas
Editor's Notes
Tumors of the Small Intestine
Small-bowel tumors comprise <3% of gastrointestinal neoplasms. Because of their rarity, a correct diagnosis is often delayed. Abdominal symptoms are usually vague and poorly defined, and conventional radiographic studies of the upper and lower intestinal tract often appear normal. Small-bowel tumors should be considered in the differential diagnosis in the following situations: (1) recurrent, unexplained episodes of crampy abdominal pain; (2) intermittent bouts of intestinal obstruction, especially in the absence of IBD or prior abdominal surgery; (3) intussusception in the adult; and (4) evidence of chronic intestinal bleeding in the presence of negative conventional contrast radiographs. A careful small-bowel barium study is the diagnostic procedure of choice; the diagnostic accuracy may be improved by infusing barium through a nasogastric tube placed into the duodenum (enteroclysis).
Tumors of the Small Intestine
Small-bowel tumors comprise <3% of gastrointestinal neoplasms. Because of their rarity, a correct diagnosis is often delayed. Abdominal symptoms are usually vague and poorly defined, and conventional radiographic studies of the upper and lower intestinal tract often appear normal. Small-bowel tumors should be considered in the differential diagnosis in the following situations: (1) recurrent, unexplained episodes of crampy abdominal pain; (2) intermittent bouts of intestinal obstruction, especially in the absence of IBD or prior abdominal surgery; (3) intussusception in the adult; and (4) evidence of chronic intestinal bleeding in the presence of negative conventional contrast radiographs. A careful small-bowel barium study is the diagnostic procedure of choice; the diagnostic accuracy may be improved by infusing barium through a nasogastric tube placed into the duodenum (enteroclysis).
not truly neoplastic but represent a hypertrophy or hyperplasia of submucosal duodenal glands. These appear as small nodules in the duodenal mucosa that secrete a highly viscous alkaline mucus. Most often, this is an incidental radiographic finding not associated with any specific clinical disorder.
About 25% of benign small-bowel tumors are polypoid adenomas (Table 87-5). They may present as single polypoid lesions or, less commonly, as papillary villous adenomas. As in the colon, the sessile or papillary form of the tumor is sometimes associated with a coexisting carcinoma. Occasionally, patients with Gardner's syndrome develop premalignant adenomas in the small bowel; such lesions are generally in the duodenum. Multiple polypoid tumors may occur throughout the small bowel (and occasionally the stomach and colorectum) in the Peutz-Jeghers syndrome. The polyps are usually hamartomas (juvenile polyps) having a low potential for malignant degeneration. Mucocutaneous melanin deposits as well as tumors of the ovary, breast, pancreas, and endometrium are also associated with this autosomal dominant condition.
Angiomas
While not true neoplasms, these lesions are important because they frequently cause intestinal bleeding. They may take the form of telangiectasia or hemangiomas. Multiple intestinal telangiectasias occur in a nonhereditary form confined to the gastrointestinal tract or as part of the hereditary Osler-Rendu-Weber syndrome. Vascular tumors may also take the form of isolated hemangiomas, most commonly in the jejunum. Angiography, especially during bleeding, is the best procedure for evaluating these lesions
Adenocarcinomas
The most common primary cancers of the small bowel are adenocarcinomas, accounting for ~50% of malignant tumors. These cancers occur most often in the distal duodenum and proximal jejunum, where they tend to ulcerate and cause hemorrhage or obstruction. Radiologically, they may be confused with chronic duodenal ulcer disease or with Crohn's disease if the patient has long-standing regional enteritis. The diagnosis is best made by endoscopy and biopsy under direct vision. Surgical resection is the treatment of choice.
Lymphomas
A diagnosis of a primary intestinal lymphoma requires histologic confirmation in a clinical setting in which palpable adenopathy and hepatosplenomegaly are absent and no evidence of lymphoma is seen on chest radiograph, CT scan, or peripheral blood smear or on bone marrow aspiration and biopsy. Symptoms referable to the small bowel are present, usually accompanied by an anatomically discernible lesion
Primary intestinal lymphoma accounts for ~20% of malignancies of the small bowel. These neoplasms are non-Hodgkin's lymphomas; they usually have a diffuse, large-cell histology and are of T cell origin. Intestinal lymphoma involves the ileum, jejunum, and duodenum, in decreasing frequency, a pattern that mirrors the relative amount of normal lymphoid cells in these anatomic areas. The risk of small-bowel lymphoma is increased in patients with a prior history of malabsorptive conditions (e.g., celiac sprue), regional enteritis, and depressed immune function due to congenital immunodeficiency syndromes, prior organ transplantation, autoimmune disorders, or AIDS.
The development of localized or nodular masses that narrow the lumen results in periumbilical pain (made worse by eating) as well as weight loss, vomiting, and occasional intestinal obstruction. The diagnosis of small-bowel lymphoma may be suspected from the appearance on contrast radiographs of patterns such as infiltration and thickening of mucosal folds, mucosal nodules, areas of irregular ulceration, or stasis of contrast material. The diagnosis can be confirmed by surgical exploration and resection of involved segments. Intestinal lymphoma can occasionally be diagnosed by peroral intestinal mucosal biopsy, but since the disease mainly involves the lamina propria, full-thickness surgical biopsies are usually required.
Resection of the tumor constitutes the initial treatment modality. While postoperative radiation therapy has been given to some patients following a total resection, most authorities favor short-term (three cycles) systemic treatment with combination chemotherapy. The frequent presence of widespread intraabdominal disease at the time of diagnosis and the occasional multicentricity of the tumor often make a total resection impossible. The probability of sustained remission or cure is ~75% in patients with localized disease but is ~25% in individuals with unresectable lymphoma. In patients whose tumors are not resected, chemotherapy may lead to bowel perforation.
A unique form of small-bowel lymphoma, diffusely involving the entire intestine, was first described in oriental Jews and Arabs and is referred to as immunoproliferative small intestinal disease (IPSID), Mediterranean lymphoma, or -heavy chain disease. This is a B cell tumor. The typical presentation includes chronic diarrhea and steatorrhea associated with vomiting and abdominal cramps; clubbing of the digits may be observed. A curious feature in many patients with IPSID is the presence in the blood and intestinal secretions of an abnormal IgA that contains a shortened -heavy chain and is devoid of light chains. It is suspected that the abnormal chains are produced by plasma cells infiltrating the small bowel. The clinical course of patients with IPSID is generally one of exacerbations and remissions, with death frequently resulting from either progressive malnutrition and wasting or the development of an aggressive lymphoma. The use of oral antibiotics such as tetracycline appears to be beneficial in the early phases of the disorder, suggesting a possible infectious etiology. Combination chemotherapy has been administered during later stages of the disease, with variable results. Results are better when antibiotics and chemotherapy are combined.
Carcinoid tumors arise from argentaffin cells of the crypts of Lieberkühn and are found from the distal duodenum to the ascending colon, areas embryologically derived from the midgut. More than 50% of intestinal carcinoids are found in the distal ileum, with most congregating close to the ileocecal valve. Most intestinal carcinoids are asymptomatic and of low malignant potential, but invasion and metastases may occur, leading to the carcinoid syndrome
Leiomyosarcomas often are >5 cm in diameter and may be palpable on abdominal examination. Bleeding, obstruction, and perforation are common. Such tumors should be analyzed for the expression of mutant c-kit receptor (defining GIST), and in the presence of metastatic disease, justifying treatment with imatinib mesylate (Gleevec) or, in imatinib refractory patients, sunitinib (Sutent).
