Stomach: Primary Gastrointestinal Lymphoma

Stomach Specific

• Stomach is the Most Common Extra-Nodal Site of Lymphoma
  • Account for 68-75% of GI Lymphomas
• Second Most Common Primary Gastric Malignancy (4%) – After Adenocarcinoma
• Most (> 50%) Present with Anemia

Small Bowel Specific

• Small Bowel is the Most Common Extra-Nodal Site of Lymphoma in the Middle East & Mediterranean Basin
• Most Common Site in Small Intestine: Ileum (Peyer Patches)
• Most Common Type: Non-Hodgkin B Cell
• T Cell Lymphoma May be Associated with Celiac Disease
• Typically Not Associated with Systemic B Symptoms

Types

• Diffuse Large B Cell Lymphoma
• Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma
  • Associated with H. pylori
• Other More Rare Types (< 10%)
  • Mantle Cell Lymphoma
  • Follicular Lymphoma
  • Peripheral T Cell Lymphoma

Prognosis

• Solitary Lesions are Rare – Maintain High Suspicion for Other Sites
• Poor Prognosis – 40-50% Survival at 5 Years

Diagnosis

• Often Diagnosed on CT (Homogenous & Well Circumscribed)
• Tissue Bx Required to Guide Treatment
• Dawson Criteria for Diagnosis of Primary GI Lymphoma:
  • No Clinically Palpable Lymphadenopathy
  • No Mediastinal Lymphadenopathy
  • Normal WBC Differential Count
  • Predominance of Bowel Lesion with Only Regional Lymph Nodes Detected
  • No Involvement of Liver/Spleen

Staging

• No Consensus on Best System
• Lugano Staging System
  • Stage I
    • I1 – Confined to Mucosa/Submucosa
    • I2 – Invades Muscularis Propria/Serosa
  • Stage II
    • II1 – Local Nodes (Gastric/Intestinal)
    • II2 – Distant Nodes (Aortic/Mesenteric)
    • IIE – Invasion of Adjacent Organs/Tissue
  • Stage IV – Supradiaphragmatic Nodes or Disseminated Disease
  • *No Stage III
• Ann Arbor Staging System with Musshoff Modification
  • Stage I: Limited to GI Tract
  • Stage II:
    • II1 – Local Nodes
    • II2 – Distant Nodes
  • Stage III: Lymph Nodes on Both Sides of the Diaphragm
  • Stage IV: Disseminated Disease
• Paris TNMB Staging System
  • T1 – Mucosa or Submucosa
  • T2 – Muscularis Propria or Subserosa
  • T3 – Serosa
  • T4 – Invasion of Surrounding Organs
  • N1 – Regional Lymph Nodes
  • N2 – Distant Intraabdominal Lymph Nodes
  • N3 – Distant Extra-Abdominal Lymph Nodes
  • M1 – Disseminated Disease
  • B1 – Metastases to Bone Marrow

Treatment

• Diffuse Large B Cell Lymphoma: Chemotherapy (CHOP) & Rituximab (R-CHOP)
• Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma
  • Early-Stage:
    • H. pylori Positive: Triple Therapy
      • Unlikely to Respond: t(11;18) or BCL-10
    • Options if Fails or H. pylori Negative:
      • XRT
      • Chemotherapy
      • Rituximab
  • Advanced-Stage (Stage IV):
    • H. pylori Positive: Triple Therapy
    • ASx: None
    • Sx: Chemotherapy or Rituximab
• Other More Rare Types
  • Mantle Cell Lymphoma: Chemotherapy & Rituximab
  • Follicular Lymphoma: XRT, Chemotherapy or Rituximab
  • Peripheral T Cell Lymphoma: Chemotherapy or Rituximab
• Indications for Resection:
  • Complete Obstruction
  • Uncontrolled Bleeding