A patient with neurological symptoms underwent CT scan that showed a sellar and suprasellar mass with bone erosions, involving especially the clivus and the right petrous apex. The first diagnostic hypothesis was chordoma in relation to the mass position. The MRI showed a solid well-enhancing mass; moreover another circumscribed lesion, with similar signal pattern, was found in the left mandibular condyle. the signal and the presence of another lesion did not agree with diagnosis of chordoma. FDG-PET/CT study showed multiple pathological uptakes suggesting a metastatic disease. A trans-sphenoidal excisional biopsy was performed and the histopathological analysis showed a population of cells consistent with a plasmacell tumor, confirmed by the presence of a monoclonal gammopathy on blood analysis. Our case suggests that FDG-PET/CT can modify the diagnostic and therapeutic procedures in myeloma, by evaluating the bone marrow involvement.
Keywords: Chordoma; FDG-PET; clivus lesion; plasmacytoma.