18F-FDG Uptake in a T2 Hypointense Paraspinal Mass

Area of Science:

• Neurology
• Pathology
• Radiology

Background:

• Spinal tumors are rare, and paraspinal masses require careful differential diagnosis.
• Amyloidomas are uncommon localized amyloid deposits, rarely presenting in the spine.
• Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (F-FDG PET/CT) is utilized for cancer staging and evaluation.

Observation:

• A solitary, F-FDG avid lesion was incidentally identified in the T11-T12 paraspinal region of a 77-year-old male patient.
• Magnetic Resonance Imaging (MRI) revealed a lesion with T2 hypointensity and contrast enhancement.
• Initial suspicion leaned towards lymphoma due to the lesion's F-FDG avidity.

Findings:

• Histopathological examination via biopsy was crucial for definitive diagnosis.
• Biopsy demonstrated nodules of extracellular, acellular, homogeneous material.
• Congo red staining exhibited characteristic apple-green birefringence, confirming amyloidoma.

Implications:

• This case highlights the importance of histopathological confirmation for paraspinal masses, even with high F-FDG uptake.
• Spinal amyloidoma is a rare entity that can mimic malignant lesions on imaging.
• Accurate diagnosis of spinal amyloidoma is essential for appropriate patient management and prognosis.