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Small Bowel Lymphoma

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Small Bowel Lymphoma

Small bowel lymphoma is a type of primary gastrointestinal (GI) lymphoma, an extranodal non-Hodgkin lymphoma that arises in the small intestine. It is less common than gastric lymphoma but is an important cause of small bowel tumors.

ICD-10

C85.99

Specialty

Gastroenterology

Onset

Chronic

Reviewed

July 2026

On This Page

Overview

    • Most primary GI lymphomas involve the stomach, small intestine, or colon.
    • Common symptoms are abdominal pain, weight loss, GI bleeding, and other nonspecific gastrointestinal complaints, making diagnosis challenging.

    The major histologic subtypes affecting the small bowel include:

    • Diffuse large B-cell lymphoma (DLBCL) – the most common primary GI lymphoma.
    • Enteropathy-associated T-cell lymphoma (EATL) – associated with celiac disease.
    • Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) – not associated with celiac disease.
    • Less commonly, Burkitt lymphoma and mantle cell lymphoma.

Etiology & Risk Factors

-Etiology

    • The cause of small bowel lymphoma depends on the subtype:
    • Diffuse large B-cell lymphoma (DLBCL):
    • May arise de novo or develop from transformation of a low-grade B-cell lymphoma (most commonly MALT lymphoma).
    • Enteropathy-associated T-cell lymphoma (EATL):
    • Occurs in patients with celiac disease, especially refractory celiac disease.
    • Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL):

Cause is unknown and is not associated with celiac disease.

-Risk Factors

    • Celiac disease (especially refractory celiac disease) → increased risk of EATL.
    • Immunocompromised state, such as:
    • HIV infection
    • Post-transplant immunosuppression
    • Transformation of preexisting low-grade B-cell lymphoma (e.g., MALT lymphoma) into DLBCL.

Pathophysiology

Malignant transformation of intestinal lymphocytes (B cells or T cells) → Uncontrolled lymphocyte proliferation → Infiltration of the small bowel wall → Bowel wall thickening + mucosal ulceration + tumor mass formation → Impaired intestinal structure and function → Bleeding, obstruction, and/or perforation

Clinical Presentation

    • Abdominal pain (most common)
    • Weight loss
    • Diarrhea
    • Nausea and vomiting
    • GI bleeding (occult or overt)
    • Palpable abdominal mass (occasionally)
    • Features of bowel obstruction (e.g., vomiting, abdominal distension)
    • Intestinal perforation (may present as an acute abdomen)
    • Constitutional (B) symptoms: fever, night sweats, weight loss

History Taking

  • Ask about:

    • When did your abdominal pain start?
    • Where is the pain located?
    • Have you lost weight without trying?
    • Do you have nausea or vomiting?
    • Do you have diarrhea?
    • Have you noticed blood in your stool or black stools?
    • Do you feel unusually tired or weak?
    • Have you had fever or night sweats?
    • Have you had bowel obstruction symptoms (severe abdominal swelling, inability to pass stool or gas)?
    • Do you have a history of celiac disease?
    • Do you have HIV or any condition that weakens your immune system?
    • Have you had an organ transplant or do you take immunosuppressive medications?
    •  

Physical Examination

  • Assess general appearance (ill-looking, weight loss)
  • Check vital signs (fever, tachycardia)
  • Look for pallor (suggesting anemia)
  • Examine for abdominal tenderness
  • Check for abdominal distension (suggesting bowel obstruction)
  • Palpate for an abdominal mass (if present)
  • Assess for signs of peritonitis (guarding, rigidity, rebound tenderness) if perforation is suspected
  • Examine for lymphadenopathy (may be present in some lymphoma subtypes)
  •  

Investigations

  • Laboratory tests

    • Complete blood count (CBC) – look for anemia
    • Basic blood tests as indicated

    Endoscopy

    • Endoscopy with biopsy (essential for diagnosis)

    Histopathology

    • Confirms the diagnosis
    • Determines the lymphoma subtype

    Immunohistochemistry

    • Identifies lymphoma markers (e.g., CD20 for B-cell lymphoma)

    Imaging (Staging)

    • CT scan
    • MRI (if indicated)
    • PET-CT for staging

     

    The definitive diagnosis of small bowel lymphoma requires biopsy with histopathology and immunohistochemistry. CT or PET-CT is used for staging.

Diagnosis

  • Diagnosis is confirmed by:

    • Endoscopy with biopsy (gold standard)
    • Histopathology to confirm lymphoma
    • Immunohistochemistry to identify the lymphoma subtype
    • CT or PET-CT for staging and assessment of disease spread

     

    The definitive diagnosis of small bowel lymphoma requires biopsy with histopathology and immunohistochemistry. Imaging is used for staging, not confirmation.

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Management

1.Medical treatment

  • Chemotherapy is the main treatment.
  • Chemoimmunotherapy for B-cell lymphomas (e.g., R-CHOP or dose-adjusted EPOCH-R).
  • Immunotherapy (e.g., rituximab) for eligible B-cell lymphomas.

2. Surgical treatment

  • Surgery is not routine.
  • Indicated for complications such as:
  • Intestinal obstruction
  • Perforation
  • GI bleeding
  • In some T-cell lymphomas (e.g., EATL), tumor-reduction surgery may be performed before chemotherapy to reduce treatment-related complications.

3. Advanced/Refractory disease

  • Autologous stem cell transplant may be considered in selected patients after chemotherapy.
  • Anti-CD19 CAR T-cell therapy may be used as second-line treatment for selected diffuse large B-cell lymphoma cases.

4. Supportive care

    • Nutritional support
    • Pain control
    • Blood transfusion if significant anemia or bleeding
    • Treat complications (infection, obstruction, perforation)

Complications

  • Intestinal obstruction
  • Intestinal perforation
  • Gastrointestinal bleeding
  • Anemia (secondary to chronic GI bleeding)
  • Malnutrition and weight loss
  • Disease progression or spread
  • Treatment-related complications (e.g., chemotherapy adverse effects)
  • The most important complications of small bowel lymphoma are intestinal obstruction, perforation, and GI bleeding, which may require urgent surgical management.

Prognosis

  • Varies by lymphoma subtype and stage at diagnosis.
  • Early diagnosis and treatment are associated with better outcomes.
  • Diffuse large B-cell lymphoma (DLBCL) generally has a better prognosis with appropriate chemoimmunotherapy.
  • Enteropathy-associated T-cell lymphoma (EATL) is often refractory to treatment and has a poorer prognosis.
  • Monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL) has a very poor response to treatment; autologous stem cell transplant may improve prognosis in selected patients

Key Points / Clinical Pearls

  • Small bowel lymphoma is a primary gastrointestinal (GI) non-Hodgkin lymphoma.
  • It most commonly affects middle-aged and older adults.
  • Diffuse large B-cell lymphoma (DLBCL) is the most common subtype.
  • Enteropathy-associated T-cell lymphoma (EATL) is strongly associated with celiac disease.
  • Common symptoms are abdominal pain, weight loss, diarrhea, nausea/vomiting, and GI bleeding.
  • Complications include intestinal obstruction, perforation, and bleeding.
  • Endoscopy with biopsy is the gold standard for diagnosis.
  • Histopathology and immunohistochemistry determine the lymphoma subtype.
  • CT or PET-CT is used for staging.
  • Chemotherapy or chemoimmunotherapy is the main treatment; surgery is reserved mainly for complications.