Fever of unknown origin in cancer patients.

Fever of unknown origin (FUO) remains a challenging clinical problem, namely in patients with cancer. In cancer patients, FUO may be due to the cancer itself, as it is the case of hematological malignancies; digestive tumors (colon cancer, liver metastases) are significantly associated with FUO and infection can be demonstrated in some cases. Prevention with G-CSF and empirical antimicrobial therapy are essential approaches for the management of FUO in cancer patients. New diagnostic approaches, such as PET imaging, should be further evaluated in cancer patients with FUO.