We report the case of a 23-year-old woman with a history of cystic fibrosis and bilung transplantation, who presented clinically cervical swollen lymph nodes with alteration of her general state. F-FDG PET/CT was performed because of lymphoma suspicion and showed cervical and pelvic hypermetabolic lymphadenopathies, with linear vaginal hypermetabolism. There was an increase of lactate dehydrogenase, and Epstein-Barr virus detection was negative. A right cervical lymph node biopsy was performed, with no lymphoma involvement. Complementary microbiological investigations showed positive results for Gardnerella vaginalis. F-FDG PET/CT lymphatic node hypermetabolism is not specific to lymphoma, particularly in immunocompromised patients.