Relapsing CNS involvement in MGUS-an Occam's razor?

Naveed Iqbal1, Navraj Chattha2, Alisha Musthafa2

  • 1Stroke Medicine, Maidstone Hospital, Maidstone, England, UK naveed.iqbal12@nhs.net.

BMJ Case Reports
|July 10, 2026
PubMed

Insights

Monoclonal gammopathy of undetermined significance (MGUS) can rarely cause central nervous system (CNS) inflammation. This case highlights a potential link between MGUS and rare CNS inflammatory lesions.

Area of Science:

  • Neurology
  • Hematology
  • Immunology

Background:

  • Monoclonal gammopathy of undetermined significance (MGUS) is typically a benign plasma cell disorder.
  • Emerging evidence suggests potential links between MGUS and organ dysfunction.
  • Central nervous system (CNS) involvement in MGUS is exceptionally rare.

Purpose of the Study:

  • To report a rare case of CNS inflammatory lesions associated with MGUS.
  • To investigate the potential pathogenic link between MGUS and CNS pathology.

Main Methods:

  • Case report of a woman in her 70s with visual disturbances.
  • Longitudinal monitoring of neurological symptoms and CNS imaging over 2 years.
  • Analysis of serum and cerebrospinal fluid using isoelectric focusing and immunofixation.

Main Results:

  • The patient developed relapsing, posterior-predominant CNS inflammatory lesions.
  • Identical paraprotein bands were found in serum and cerebrospinal fluid.
  • No alternative diagnoses like multiple sclerosis or CNS lymphoma were identified.

Conclusions:

  • This case suggests a possible pathogenic association between MGUS and CNS inflammatory disease.
  • MGUS should be considered in the differential diagnosis of unexplained CNS inflammatory lesions.
  • Further research is needed to understand the mechanisms and implications of CNS involvement in MGUS.

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