title: False-positive axillary lymph node on FDG-PET/CT scan resulting from immunization.
abstract: An initial CT of a 59-year-old man with increasing back pain and weight loss showed lymphadenopathy in multiple nodal beds. A biopsy showed diffuse, large B-cell lymphoma (DLBCL). After initial chemotherapy, residual disease prompted an autologous stem cell transplant. After a follow-up FDG-PET/CT scan showed no FDG-avid disease, a subsequent study showed FDG uptake in a nonenlarged left axillary lymph node. Questioning elicited a recent immunization history. A follow-up PET/CT scan showed no uptake in this lymph node and no disease recurrence. Without this history, an unnecessary biopsy or treatment may have ensued. Methods to avoid such occurrences are discussed.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Beth Israel Deaconess Medical Center, Boston, MA 02215-5400, USA.
authors.forename: Gethin
authors.initials: G
authors.lastname: Williams
authors.forename: Robin M
authors.initials: RM
authors.lastname: Joyce
authors.forename: J Anthony
authors.initials: JA
authors.lastname: Parker
mesh_terms: D001365:Axilla / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control; D005189:False Positive Reactions; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007114:Immunization; D008198:Lymph Nodes / Q000000981:diagnostic imaging* / Q000187:drug effects; D008207:Lymphatic Metastasis; D016393:Lymphoma, B-Cell / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014765:Viral Vaccines / Q000008:administration & dosage*
chemical_list: D019275:Radiopharmaceuticals; D014765:Viral Vaccines; D019788:Fluorodeoxyglucose F18