Primary Pancreatic Lymphoma on FDG PET/CT

Area of Science:

• Oncology
• Nuclear Medicine
• Pathology

Background:

• Positron Emission Tomography/Computed Tomography (PET/CT) with Fluorodeoxyglucose (FDG) is a key imaging modality for evaluating abdominal masses.
• Distinguishing between pancreatic malignancy and other abdominal pathologies can be challenging.
• Lymphoma can occasionally present as a pancreatic head mass, mimicking primary pancreatic cancer.

Observation:

• A 69-year-old male presented with a right upper abdominal mass.
• FDG PET/CT revealed a pancreatic head mass with peripheral hypermetabolism and a central photopenic area.
• This imaging pattern initially suggested pancreatic adenocarcinoma.

Findings:

• Histopathology confirmed the pancreatic mass as diffuse large B-cell lymphoma (DLBCL).
• FDG PET/CT demonstrated a significant decrease in radiotracer uptake in the pancreatic mass after 8 cycles of chemotherapy.
• This indicates a positive response to treatment.

Implications:

• FDG PET/CT is valuable in the diagnosis and treatment response assessment of pancreatic masses.
• The imaging findings highlight the importance of considering extranodal lymphoma in the differential diagnosis of pancreatic head masses.
• Chemotherapy effectively reduced metabolic activity in the pancreatic lymphoma, as shown by follow-up imaging.