Expression of Glucose Transporter-1, Hypoxia-Inducible Factor-1α, Phosphatidylinositol 3-Kinase and Protein Kinase B (Akt) in Relation to [ ¹⁸ F]Fluorodeoxyglucose Uptake in Nasopharyngeal Diffuse Large B-Cell Lymphoma: A Case Report and Literature Review

This report presents a case of nasopharyngeal diffuse large B-cell lymphoma and a literature review concerning the use of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). A 37-year old man was admitted to hospital complaining of nasal secretions with minor epistaxis and a 20-year history of snoring. Nasal endoscopy found diffuse swelling in the nasopharynx and a biopsy was performed. Prior to chemotherapy, FDG-PET/CT showed soft tissue diffuse thickening and FDG accumulation in the nasopharynx and bilateral cervical lymph nodes; FDG did not accumulate elsewhere. After four cycles of chemotherapy (rituximab, cyclo phosphamide, doxorubicin, vincristine) and prednisone treatment, FDG-PET/CT showed that FDG still accumulated in the nasopharynx and bilateral cervical lymph nodes, therefore radiotherapy was initiated. At 1 year, FDG-PET/CT showed no FDG accumulation. Immunohistochemical analysis revealed that the tumour was positive for phosphorylated protein kinase B (Akt), suggesting that FDG uptake may be associated with factors activated by the phosphatidylinositol 3-kinase/Akt signalling pathway.