Oligosecretory multiple myeloma: a devastating presentation of a difficult diagnosis

Area of Science:

• Oncology
• Hematology
• Nephrology

Background:

• Multiple Myeloma (MM) is a plasma cell malignancy typically characterized by specific clinical and laboratory findings.
• Atypical presentations of MM can pose diagnostic challenges, potentially delaying appropriate management.
• Oligosecretory MM, a subtype with minimal or no detectable monoclonal protein in serum or urine, represents a diagnostic hurdle.

Observation:

• A 57-year-old male presented with lumbar pain and fever, initially diagnosed as spondylodiscitis, progressing to paraplegia.
• Imaging revealed a D9 vertebral mass with osteolytic lesions, and biopsy confirmed a plasmacytoma.
• Despite initial bone marrow findings, skeletal lesions suggested multiple myeloma (MM), later confirmed.
• The patient exhibited rare IgA and lambda light chain production with normal uninvolved immunoglobulins, indicative of oligosecretory MM.

Findings:

• The diagnosis of oligosecretory multiple myeloma (MM) was confirmed via an altered free light chain (FLC) assay.
• The patient's presentation highlighted the diagnostic challenges posed by atypical MM, including medullary compression syndrome.
• Rare production of IgA and lambda chains alongside normal immunoglobulin levels complicated the diagnostic pathway.

Implications:

• Delayed diagnosis of oligosecretory MM can lead to severe patient morbidity and mortality.
• The free light chain (FLC) assay is essential for the early and accurate diagnosis of suspected multiple myeloma (MM) cases.
• This case underscores the importance of considering less common MM subtypes and utilizing advanced diagnostic tools.