This case describes a rare salmonella infection suspected to be an osseous lymphoma. A 27-year-old female presented herself with painful swelling of her knee, with prednisolone-treated Crohn's disease as her only pre-existing condition. Salmonella species group C were detected in the osseous material derived from an extraction. The disease was treated with intravenous ceftriaxone, oral cotrimoxazole as well as multiple debridements. The working diagnosis should thus always be questioned and bone pain in patients who are immunosuppressed should be further investigated.
