Heterogeneity and Evolution of 68 Ga-Pentixafor PET/CT Signals in Extramedullary Multiple Myeloma.
Mengjing Ji, Yutong Ye, Lingyu Ma et al.
✦ AI-curated · Sources linked
Case in brief
A 55-year-old man with multiple myeloma presented for 68 Ga-pentixafor PET/CT, revealing an extramedullary soft-tissue lesion misidentified as a mesenchymal tumor due to low tracer uptake. After standard therapy, while bone marrow disease was controlled, the extramedullary lesion exhibited increased uptake and size. Immunohistochemistry confirmed it as extramedullary disease from multiple myeloma, highlighting diagnostic challenges.
What made this case unusual
The extramedullary lesion displayed low tracer avidity and marked uptake heterogeneity, complicating its initial diagnosis.
Diagnostic / clinical pearl
Clinicians should be aware that low-CXCR4-avid extramedullary lesions in multiple myeloma can lead to misdiagnosis and may require careful monitoring.
Why it matters
This case underscores the importance of considering extramedullary disease in multiple myeloma, especially when imaging findings are atypical.