In this paper, we present a male patient from Xinjiang with fever of unknown origin and significant weight loss for more than 1 month. He was admitted to hospital with negative Rose Bengal test (RBT) and decreased leucocyte count. Ultrasound revealed splenomegaly and abdominal computed tomography,which showed multiple hypodense splenic nodules. The patient was suspected of lymphoma or tuberculosis. Pathological biopsy suggested brucellosis infection following splenectomy. Anti-Brucella treatment was effective and his temperature gradually returned to normal. During the follow-up, the patient’s RBT result turned to positive and he was instructed to continue the anti-Brucella drug regimen. His temperature, weight, white blood cell count, other laboratory examinations, and imaging findings all returned to normal during the 6-month follow-up after the treatment.