FDG uptake in cervical lymph nodes in children without head and neck cancer

Reactive cervical lymphadenopathy is common in children and may demonstrate increased F-18-fluoro-deoxyglucose (F-18-FDG) uptake on positron emission tomography/computed tomography (PET/CT). We sought to evaluate the frequency and significance of F-18-FDG uptake by neck lymph nodes in children with no history of head and neck cancer. The charts of 244 patients (114 female, mean age: 10.4 years) with a variety of tumors such as lymphoma and post-transplant lymphoproliferative diseases (PTLD), but no head and neck cancers, who had undergone F-18-FDG PET/CT were reviewed retrospectively. Using the maximum standardized uptake value (SUVmax), increased F-18-FDG uptake by neck lymph nodes was recorded and compared with the final diagnosis based on follow-up studies or biopsy results. Neck lymph node uptake was identified in 70/244 (28.6%) of the patients. In 38 patients, the lymph nodes were benign. In eight patients, the lymph nodes were malignant (seven PTLD and one lymphoma). In 24 patients, we were not able to confirm the final diagnosis. Seven out of the eight malignant lymph nodes were positive for PTLD. The mean SUVmax was significantly higher in malignant lesions (4.2) compared with benign lesions (2.1) (P = 0.00049). F-18-FDG uptake in neck lymph nodes is common in children and is frequently due to reactive lymph nodes, especially when the SUVmax is < 3.2. The frequency of malignant cervical lymph nodes is higher in PTLD patients compared with other groups.