Small Intestine Tumors, Malignant

• • Often symptomatic

  • -Abdominal pain most common presenting complaint

  • Circumferential luminal growth results in progressive obstruction

  • Bleeding is a feature of ulcerated tumors

  • Besides primary neoplasms, the small bowel may be a site of metastatic disease

  • Diagnosis usually radiographic by contrast study or CT scan

  • Resection indicated for cure and palliation

Epidemiology

Adenocarcinoma

• • 50% of cases

  • Risk factors include:

  • -Crohn disease

    -Polyposis syndromes

    -Villous adenomas

    -Family history of nonpolyposis colorectal cancer

Lymphoma

• • 15-20% of cases

  • Most common extranodal lymphoma

  • May be primary or part of disseminated disease

  • Most are non-Hodgkin B-cell

  • More common in the ileum

  • Risk factors include:

  • -Malabsorption

    -Inflammatory intestinal disease

    -Immunosuppression

Stromal Tumors

• • 10-20% of cases

  • Distinction between benign and malignant difficult

  • Tumors are extraluminal and subserosal

  • Metastases present in 30% at presentation

Metastatic Tumors

• • Affect small bowel by direct extension, carcinomatosis, or hematogenous spread

Symptoms and Signs

• • Abdominal pain

  • GI bleeding

  • Malabsorption (lymphoma)

  • Weight loss

  • Abdominal distention

  • Abdominal tenderness

  • Palpable abdominal mass (stromal tumor)

Laboratory Findings

• • Anemia

Imaging Findings

Adenocarcinoma

• • Radiographic contrast study

  • -Annular with ulcerated mucosa

    -"Apple core" appearance

  • CT scan: Detection of metastases and staging

Lymphoma

• • Radiographic contrast study: Thickened mucosa, ulceration, submucosal nodules

  • CT scan

  • -Diffuse bowel wall thickening, mesenteric adenopathy, mass lesion

    -Detection of metastases and staging

Stromal Tumors

• • Radiographic contrast study

  • -Extraluminal mass

    -Central necrosis with contrast filling

  • CT scan

  • -Extraluminal mass with vascularity and central necrosis

    -Detection of metastases and staging

• • Most small intestinal tumors are not accessible by endoscopy and diagnosis relies on symptoms, radiographic appearance, and clinical suspicion

  • Differentiating benign and malignant stromal tumors based on mitotic frequency, nuclear atypia, cellularity, size of tumor, and central necrosis

Rule Out

• • Benign tumors of the small intestine

• • CBC

  • GI contrast radiograph study

  • CT scan

  • Endoscopy and biopsy (if lesion is accessible)

When to Admit

• • High-grade obstruction

  • Bleeding

Surgery

• • All malignant tumors require wide segmental resection

  • Even if not curative, resection may palliate obstruction and bleeding

Indications

• • All malignant tumors

Medications

• • Chemotherapy and radiation therapy have proved beneficial for lymphoma

  • Imatinib mesylate for stromal tumors

Complications