FDG-PET/CT imaging in the evaluation of lymphadenopathy seen in patients wih lymphoma with or without the presence of associated HIV infection

Objectives lymphadenopathy is very common in individuals affected by HIV infection.This study analyses the incidence of active cervical, axillary and inguinal lymphadenopathy in patients with lymphoma with or without HIV infection that were referred for PET/CT imaging.

Methods fifty four PET/CT scans performed in 41 patients suffering from lymphoma associated with HIV infection (15 initial staging, 34 restaging, 5 evaluation of treatment response) [G1] were compared to 51 PET/CT scans in 41 age and gender matched patients with lymphoma not associated with HIV infection (3 initial staging, 34 restaging, 14 evaluation of treatment response) [G2]. The CD4 T cell count and viral load done in G1 at the time around PET/CT imaging were retrieved from the laboratory for analysis.

Results active lymphadenopathy on PET/CT was commonly visualized in G1; cervical: 30 (73.2%) vs 10 (24.4%) {p=0.001}; axillary: 17 (41.5%) vs 8 (19.5%) {p=0.04); inguinal: 15 (36.6%) vs 6 (14.6%) {p=0.03}. The CD4 T cell count and the viral load were available in 34 (82.9%) and 24 (58.5%) patients, respectively. There was a strong association between the incidence of active lymphadenomaty and HIV status of the patients (r=0.31; p=0.001).

Conclusions the largest study to date that looks at PET/CT scanning in lymphoma associated with HIV included 7 patients. Our study with 41 patients demonstrated an association between the presence of active lymphadenopathy on PET/CT and the HIV infection. Active lymphadenopathy visualized in the cervical, axillary and inguinal regions on PET/CT done in patients with lymphoma and associated HIV infection cannot simply be considered metastatic in nature. We would advise that FNA cytology should become a routine part in the management of patients with FDG uptake in cervical, axillary or inguinal lymphadenopathy whenever these sites are the only positive findings on PET/CT performed to evaluate treatment response, prior to therapeutic decision