Multiple myeloma presenting with acquired factor VIII inhibitor

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• Acquired Factor VIII inhibitors are rare, particularly in conjunction with hematological malignancies.
• Multiple myeloma presenting with an acquired FVIII inhibitor is exceptionally uncommon, with only one prior documented case.

Observation:

• A 43-year-old woman with a history of ovarian cyst rupture and severe bleeding presented with anemia and elevated inflammatory markers.
• Coagulation tests revealed a prolonged partial thromboplastin time, decreased Factor VIII levels, and an uncorrectable mixing test, indicating an acquired FVIII inhibitor.
• Further investigations confirmed multiple myeloma (IgG kappa type) with lytic bone lesions and significant plasma cell infiltration.

Findings:

• The patient was diagnosed with IgG kappa multiple myeloma associated with an acquired Factor VIII inhibitor.
• This represents the second documented case of multiple myeloma presenting with an acquired FVIII inhibitor.

Implications:

• Autoantibodies against Factor VIII should be considered in the differential diagnosis for patients presenting with severe bleeding.
• Clinicians must maintain a high index of suspicion for rare underlying neoplastic diseases, such as multiple myeloma, in patients diagnosed with acquired FVIII inhibitors.