Exceptional Thyroid Recurrence of Solitary Bone Plasmacytoma Detected by 18 F-FDG PET/CT.
Jean-Michel Leclere, Jean-Christophe Leclere, Alexis Chambost et al.
✦ AI-curated · Sources linked
Case in brief
A 70-year-old man previously treated with radiotherapy for solitary bone plasmacytoma of the left hemipelvis underwent 18 F-FDG PET/CT follow-up. Imaging showed focal hypermetabolism in the right thyroid lobe without other abnormalities. Ultrasound classified the nodule as EU-TIRADS 5, while cytology was indeterminate (Bethesda III). Core biopsy established thyroid plasmacytoma, identifying an extramedullary recurrence at a distant site.
What made this case unusual
The recurrence involved the thyroid, an exceedingly rare site of involvement by solitary bone plasmacytoma, rather than presenting as progression to multiple myeloma.
Diagnostic / clinical pearl
In a patient with prior plasmacytoma, a suspicious thyroid lesion may represent extramedullary relapse; indeterminate cytology may require core biopsy for diagnosis.
Why it matters
The case illustrates how 18 F-FDG PET/CT can detect an otherwise unsuspected thyroid focus during follow-up, while tissue confirmation establishes its nature.