FDG PET/CT in a Patient With Syphilis Suspected of Having Penile Cancer

Abstract

A 58-year-old man with large penile wound and enlarged regional lymph node was suspected of having disseminated penile cancer. FDG PET/ CT for primary staging showed high FDG uptake on penis and in several enlarged lymph nodes. However, biopsies revealed no signs of malignancy, but ulceration, inflammation, fibrosis, and spirochetes. Furthermore, Wassermann test was positive. The patient was then treated for syphilis. To our knowledge, this is the first report on FDG PET/CT in a patient suspected of having penile cancer that turned out to be syphilis. Thus, syphilis can be added to the list of benign pitfalls in FDG PET/CT.

Syphilis Mimicking Malignant Pulmonary Tumor With Nodal and Bone Metastasis on 18F-FDG PET/CT

“…[5][6][7][8] Syphilis has been known as the "great imitator," and it is still a diagnostic challenge to nuclear medicine physicians due to the syphilitic-related lesions with a high FDG uptake mimicking malignancy. [5][6][7]9,10 Nevertheless, after the knowledge of the syphilis existence, PET/CT scans help us in the diagnosis, showing the extension of the disease, guiding the therapeutic intervention and in the follow-up showing treatment response assessment. 5…”