Primary bone lymphoma presenting as fever of unknown origin.

We presented a case of primary bone lymphoma (PBL) which demonstrated fever of unknown origin. Although the diagnosis of PBL is difficult, up to 11% of patients with fever of unknown origin were later diagnosed with PBL, which suggests that there may be many cases of misdiagnosis. This case study emphasizes the importance of careful diagnosis for fever of unknown origin especially when the patient has bone pain.