MALT lymphoma (dura)

MALT lymphomas of the dura (also known as extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue of the dura), are an uncommon form of CNS lymphoma, accounting for an even smaller proportion of dural masses. They are, however, the most common form of primary dural lymphoma

Unlike other CNS lymphomas that are of large B-cell lineage, primary dural lymphomas are related to mucosa-associated lymphoid tissue (MALT), and as a result, have an indolent course and far better prognosis. On imaging, they are difficult to diagnose pre-operatively as primary dural lymphomas share many similarities with meningiomas which are vastly more frequent.

For a discussion of extracranial disease, see MALT lymphoma

MALT lymphoma of the dura are most often encountered in middle-aged individuals, more commonly in females. They account for < 1% of all CNS lymphoma 1,2

Presentation is usually indolent with symptoms related to mass effect, without features helpful in distinguishing them from meningiomas 1

Unlike other primary CNS lymphomas which are usually of non-Hodgkin B-cell lineage, primary dural lymphomas tend to arise from mucosa-associated lymphoid tissue (MALT), although how and why this is the case so far remains unclear 1 (see MALT lymphoma for a general discussion).

Microscopic appearance

As is the case with MALT lymphomas elsewhere, these tumours are composed of small rounded lymphocytes, marginal zone cells and plasma cells 2

Immunophenotype
  • CD5: negative
  • CD10: negative B-cells

The vast majority of MALT lymphomas of the dura arise in the intracranial compartment 2

Primary dural lymphoma shares imaging features with other small round blue cell tumours, and other dural masses. These tumours present as an extra-axial lobulated mass, that may be either solitary or multiple and are difficult to distinguish from meningiomas. 

CT

Due to high cellularity, these tumours are typically somewhat hyperdense compared to brain (as are other CNS lymphomas) 1. They generally enhance vividly. 

MRI
  • T1: isodense to grey matter
  • T1 C+
    • vivid enhancement (usually homogeneous)
    • brain tumour interface may be indistinct
  • T2
    • iso to hypodense to grey matter
    • oedema common in adjacent brain
  • DWI/ADC: restricted diffusion

Primary dural lymphomas are non-aggressive and patients have excellent outcomes regardless of treatment 1,2

The differential diagnosis is essentially that of other dural masses, including: 

Lymphoma
Share article

Article information

rID: 32688
Section: Pathology
Tags: refs, cases
Synonyms or Alternate Spellings:
  • Primary dural lymphomas
  • Primary dural lymphoma

Support Radiopaedia and see fewer ads

Updating… Please wait.
Loadinganimation

Alert accept

Error Unable to process the form. Check for errors and try again.

Alert accept Thank you for updating your details.