Incidental Diagnosis of Diffuse Large B-Cell Lymphoma by 11C-Choline PET/CT in a Patient With Biochemical Recurrence of Prostate Cancer

The main indication for C-11-choline PET/CT in prostate cancer patients is the early localization of biochemical recurrence after radical treatment. However, any C-11-choline uptake should be assessed in terms of physiological distribution and patterns of tumor spread. Therefore, tracer-avid lesions in unexpected sites should be carefully addressed because the diagnosis of other malignancies has important therapeutic implications. We present a patient with biochemical recurrence of prostate cancer treated with radiotherapy. C-11-choline PET/CT showed local recurrence and inguinal lymph node uptake. Because of its location beyond typically prostatic lymphatic spread, resection was performed. Histology confirmed a diffuse large B-cell lymphoma.