Marginal Zone B-cell lymphoma (MALT lymphoma)


Low-grade malignant non-Hodgkin lymphoma (NHL) that develops in mucosa-associated lymphoid tissue (MALT).

  • #3 M/C lymphoma (7-8% of NHLs)
  • Only NHL which is more common in females
Bowzyk Al-Naeeb, A., Ajithkumar, T., Behan, S., & Hodson, D. J. (2018). Non-Hodgkin lymphoma. BMJ, 362, k3204.


Autoimmune diseases:

  • Sjögren syndrome (SjS): Salivary gland MALToma
  • Hashimoto thyroiditis: Thyroid MALToma

Chronic inflammation (due to infection):

  • Borrelia burgdorferi: Cutaneous MALToma
  • H. pylori: Gastritis → Gastric MALToma (M/C)
  • HCV: Splenic MALToma
  • Chlamydia psittaci: Conjunctivitis → Ocular MALToma


Genetic hallmark: t (11,18) > t (14,18)


Clinical features

Nodal MALToma:

  • Painless lymphadenopathy

Extranodal MALToma:

  • Gastric MALToma: Nausea, vomiting, anaemia, mass effect
  • Salivary, thyroid MALToma: Mass effect → Dysphagia
  • Lungs: Cough

Splenic MALToma:

  • Splenomegaly
  • Abdominal discomfort

B symptoms:

  • Fevers, chills, night sweats or unexplained weight loss >10% of body weight
  • Frequent in patients with advanced-stage or bulky disease
The Calgary Guide |


Core-needle/excisional biopsy (no FNAC):

  • Immunophenotype: CD19, CD79a,CD 20, surface Ig
Histological findings. (A) Low power view of the one specimen of colon biopsies. Severe atypical lymphoid infiltrates are seen. (B) High power view. It is evident that the lymphoid infiltrates are composed of atypical small lymphocytes reminiscent of centrocytes-like features. Monocytoid atypical cells, plasmacytoid atypical cells, and immunoblastic cells were seen. Mitotic figures were also seen. Germinal centers and lymphepithelial lesions are seen. (A): hematoxylin and eosin (H and E), ×100. (B) (H and E), ×200 | Terada T. (2014). Extranodal marginal zone B-cell lymphoma of Mucosa-Associated Lymphoid Tissue (MALT lymphoma) in ulcerative colitis. Saudi journal of gastroenterology : official journal of the Saudi Gastroenterology Association, 20(5), 319–322. doi:10.4103/1319-3767.141696


Ann Arbor staging system with Cotswolds modification:

Staging system for lymphomas, both in Hodgkin’s lymphoma (formerly designated Hodgkin’s disease) and non-Hodgkin lymphoma (abbreviated NHL)

  • Principal stages (determined by location):
    • Stage I: Single site (nodal/extranodal)
    • Stage II: ≥ 2 LN on same side of diaphragm (number of anatomic sites should be indicated in a suffix: e.g. II2)
    • Stage III: LN/structures on both sides of diaphragm:
      • III1: With/without splenic, hilar, celiac or portal nodes
      • III2: With paraaortic, iliac or mesenteric nodes
    • Stage IV: Diffuse, disseminated, several extranodal ± nodal involvement
  • Modifiers (can be appended to some stages):
    • A: No B symptoms
    • B: B symptoms present
    • S (spleen)
    • “extranodal”
    • (largest deposit is >10 cm large (“bulky disease”), or whether the mediastinum is wider than ⅓ of the chest on a chest X-ray)

St.Jude’s/Murphy classification: Pediatric NHL


  • Asymptomatic cases:
    • Antibiotics (CURATIVE): For underlying infections
  • Localised disease:
    • Local radiotherapy
  • Disseminated disease:
    • Single-agent chemotherapy: Chlorambucil or bendomustine/lenalidomide
  • Splenic MALToma: Splenectomy
  • DLBCL: R-CHOP regimen


International prognostic index (IPI):

  • Age > 60 years
  • ↑ Serum lactate dehydrogenase (LDH)
  • Performance status ≥ 2 (ECOG) or ≤70 (Karnofsky)
  • Ann Arbor Stage III/IV
  • ≥ 2 sites of extranodal involvement

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