Small bowel neoplasms

1. Small bowel neoplasms
Dr nawin kumar

2. General Considerations
• Small bowel neoplasms are exceedingly rare
– 80% of the total length
– 5% of all GIT neoplasms
– 1% - 2% of all malignant tumors of the GIT
• factors
– rapid transit of luminal contents;
– high turnover rate epithelial cells
– alkalinity of small intestinal contents;
– the high level of IgA in the intestinal wall
– low bacterial count.

3. • equally distributed between men and women
• age - old
• geographic distribution-
– highest cancer rates found among the Maori of
New Zealand and ethnic Hawaiians.
– low in India, Romania

4. • most benign neoplasms are asymptomatic
• found as an incidental finding.
• Benign
– Leiomyomas and adenomas are the most frequent
– more common in the distal small bowel
– per unit area, duodenal tumors are most frequent.
• most common malignant neoplasm.
– adenocarcinoma
– carcinoid tumor
• site
– Adenocarcinomas - proximal small bowel,
– other malignant lesions - in the distal intestine

5. • risk
– Crohn's disease
– familial adenomatous polyposis
– hereditary nonpolyposis colorectal cancer (HNPCC)
– Peutz-Jeghers syndrome,
– gluten-sensitive enteropathy (i.e., celiac sprue),
– biliary diversion (e.g., previous cholecystectomy).
• Controversial factors –
– smoking,
– heavy alcohol consumption
– red meat
– salt-cured foods.

6. Diagnosis
• Plain films – obstruction
• Angiography is - tumors of vascular origin.
• CT –
– extraluminal tumors such as (GISTs)
– staging of malignant cancers
• Ultrasonography not proved to be effective
• Barium follow through
• CT enteroclysis
• Flexible -duodenal lesions
• colonoscope - terminal ileum
• Push enteroscopy
• radiotelemetry capsules (e.g., capsule endoscopy)
• surgical exploration

7. Benign Neoplasms
• most common
– benign GISTs- most common that produce
symptoms
– adenomas- most common in autopsy
– lipomas.

8. Clinical Manifestations
• Most patients asymptomatic
• often nonspecific
– dyspepsia,
– anorexia,
– malaise,
– dull abdominal pain (often intermittent and
colicky).

9. Treatment
• risk for subsequent complications
– obstruction – intussusceptions
– Hemorrhage - usually occult; hematochezia or
hematemesis may occur
– For final diagnosis - microscopic evaluation.
• polypectomy
• Segmental resection and primary anastomosis
• very small lesions- enterotomy.
• entire small bowel searched - multiple.
• pancreaticoduodenectomy

10. GISTs
• arise from the interstitial cell of Cajal,
• intestinal pacemaker cell of mesodermal
descent.
• incidence is equal in men and in women,
• age - fifth decade of life

11. • intramurally - obstruction.
• extramural growth-
– achieving considerable size
– outgrowing their blood supply –
• ischaemic pain,
• bleeding

12. • Grossly,
– firm, gray-white
– whorled appearance on cut surface;
• microscopic examination
– well-differentiated smooth muscle cells.
– spindle (70%) and epithelioid (30%) cells,
– Most (>90%) GISTs express CD117,
– c-kit proto-oncogene transmembrane protein
– receptor for the stem cell growth factor,
– 70% to 80% express CD34, the human progenitor cell
antigen;
– Sometime actin and desmin

13. Adenomas
• 15% of all benign small bowel tumors
• Most common as asymptomatic
• three primary types:
– true adenomas,
– villous adenomas
– Brunner gland adenomas.
• Site
– 20%- duodenum,
– 30% - jejunum,
– 50% - ileum.

14. • Villous adenomas
– rare
– most commonly - duodenum,
– may be with FAP
– propensity for malignant degeneration
• Brunner gland adenomas –
– produce symptoms mimicking those of peptic
ulcer disease.

15. Lipomas
• Usually- single intramural lesions located in
the submucosa.
• intusception

16. Hamartomas of the small bowel
• as part of the Peutz-Jeghers syndrome,
• an inherited syndrome of mucocutaneous
melanotic pigmentation and gastrointestinal
polyps.
• The pattern of inheritance is simple mendelian
dominant with a high degree of penetrance

17. • classic pigmented lesions
– small, 1- to 2-mm,
– brown or black spots
– location
• circumoral region of the face, buccal mucosa,
• forearms, palms, soles, digits,
• perianal area.
• entire jejunum and ileum
– may rectal and colonic lesions, gastric lesions.

18. • symptom
– most common- colicky abdominal pain-
intermittent intussusception.
– Hemorrhage –
• Frank- autoamputation of the polyps
• anemia.
• Extracolonic cancers are common- small
intestine

19. • treatment –
– directed to presentation
– limited resection.
– widespread nature of intestinal involvement, cure
is not possible

20. Hemangiomas
• developmental malformations
• submucosal proliferation of blood vessels.
• Jejunum - most commonly affected but can involve any GIT
• Rare
• multiple in 60% of patients.
• may occur as part
– Osler-Weber-Rendu disease.
– Turner's syndrome
• Angiography and 99mTc–red blood cell scanning are the
most useful diagnostic studies.
• intraoperative transillumination and palpation
• Segmental resection

21. Malignant
• Carcinoid tumors
• may arise in organs derived from the foregut,
midgut, and hindgut.
• upto 80% of carcinoids are asymptomatic and
found incidentally
• more than 90% in three sites:
– the appendix (45%),
– the ileum (28%), and
– the rectum (16%)
AIR

22. • The malignant potential (ability to metastasize) is
related to
• location,
– Only 3% of appendiceal carcinoids metastasize,
– but 35% of ileal carcinoids gets metastasis
• size,
– <1 cm in diameter- 2% metastasis. In contrast,
– 1 to 2 cm in diameter 50% metastasis
– > 2 cm in diameter 90% metastasis
• depth of invasion,
• growth pattern

23. • Grossly
– small, firm submucosal nodules
– multicentric in 20% to 30%
– usually yellow on cut surface
• grow very slowly,
• after invasion of the serosa-
• intense desmoplastic reaction producing mesenteric
fibrosis, intestinal kinking, and intermittent obstruction.
Small bowel carcinoids are of patients.
• frequent coexistence of a second primary malignant
synchronous adenocarcinoma
• associated with MEN 1 in about 10% of cases.

24. • Clinical Manifestations
– Local symptom- similar to other small bowel
tumors
– carcinoid syndrome

25. • Malignant Carcinoid Syndrome
• relatively rare disease < 10% of patients
• humoral factors
– serotonin,
– 5-hydroxytryptophan (a precursor of serotonin synthesis),
– histamine,
– dopamine,
– kallikrein,
– substance P,
– prostaglandin,
– neuropeptide K

26. • requirement
– massive hepatic replacement by metastatic disease.
– bypass the liver, specifically ovarian and retroperitoneal
carcinoids,
• includes
– vasomotor-
• cutaneous flushing
• asthma
– cardiac,
• pulmonary stenosis
• tricuspid insufficiency
• tricuspid stenosis
– gastrointestinal manifestations.
• diarrhea (76%);
• hepatomegaly

27. • Cutaneous flushing - four varieties:
• diffuse erythematous,
– short lived
– normally affects the face, neck, and upper chest;
• violaceous,
– similar to diffuse erythematous flush
– attacks may be longer
– patients may develop a permanent cyanotic flush with watery eyes and
injected conjunctivae;
• prolonged flushes,
– last up to 2 to 3 days
– involve the entire body
– profuse lacrimation, hypotension, and facial edema;
• bright-red patchy flushing,
– which is typically seen with gastric carcinoids.
• diarrhea
– episodic (usually occurring after meals),
– watery, and often explosive

28. • Diagnosis
• various humoral factors
– urinary levels of 5-HIAA measured over 24 hours
• serotonin -liver and lung -inactive 5-hydroxyindoleacetic
– plasma concentrations of chromogranin A
– Plasma serotonin, substance P, neurotensin, neurokinin A, and
neuropeptide K
• Provocative tests using pentagastrin, calcium, or epinephrine may
be used to reproduce the symptoms of carcinoid tumors.
• Barium radiographic studies –
• multiple filling defects - kinking and fibrosis of the bowel
• Angiography
• high-resolution ultrasonography
• somatostatin receptor scintigraphy using 111In-labeled
pentetreotide.

29. Treatment
• based on
– tumor size and site
– presence or absence of metastatic disease
• <1 cm + no metastasis- a segmental intestinal
resection
• > 1 cm, with multiple tumors + metastasis, -wide
excision of bowel and mesentery is required.
• Lesions of the terminal ileum - right
hemicolectomy.
• duodenal - pancreaticoduodenectomy.

30. • metastatic disease- surgical debulking,
• hepatic metastases-
– wedge resection or formal hepatic lobectomy.
– hepatic artery ligation or percutaneous
embolization

31. • Medical therapy -relief of symptoms caused by
the excess production of humoral factors.
• analogues of somatostatin, such as octreotide
• Interferon-α
• Serotonin receptor antagonists –
– Methysergide - retroperitoneal fibrosis.
– Ketanserin and cyproheptadine
• Cytotoxic chemotherapy -limited success.
– streptozotocin and 5-fluorouracil or
cyclophosphamide

32. • Prognosis
• Carcinoid tumors have the best prognosis of
all small bowel tumors,
– Resection of a carcinoid tumor localized - 100%
survival rate.
– Five-year survival rates are about 65% among
patients with regional disease and
– 25% to 35% among those with distant metastasis

33. • carcinoid crisis during anaesthesia
– hypotension,
– bronchospasm,
– flushing,
– tachycardia to arrhythmias.
• The treatment - IV octreotide, antihistamine,
hydrocortisone