The Key Role of Splenectomy in Fever of unknown Origin which Resulted to be B-cell primary Splenic Lymphoma.

Background: The term ‘fever of unknown origin’ (FUO) was first introduced by Petersdorf and Beeson in 1961, and it is defined as recurrent fever >38.3°C, lasting for >3 weeks, remaining undiagnosed after 1 week of in-hospital evaluation. The etiologies of classic FUO include mainly infections, malignancies, non-infectious inflammatory diseases, and miscellaneous causes, while some cases remain undiagnosed. Primary splenic lymphoma (PSL) is a rare malignant lymphoma. In many cases, splenectomy is the treatment of choice for massive splenomegaly. Case presentation: A 54-year-old woman presented with a history of high fever up to 39°C, sweating, fatigue, and weight loss for one month. She had been treated by her family physician with antibiotics (cephalosporin) for 10 days but without improvement. On admission, the patient had palpable splenomegaly but no palpable lymphadenopathy. The patient had increased markers of inflammation. The indicators of autoimmune disease were all negative. Screening for specific infectious diseases and the blood cultures all came out negative. Abdominal computerized tomography (CT) revealed an enlarged spleen. The splenectomy was performed and the spleen was sent for histological analysis. Meanwhile, the patient was subject to a complex treatment. Histological and immunohistochemical analysis confirmed the diagnosis of diffuse large B-cell non-Hodgkin lymphoma with diffuse red pulp infiltration. Afterward, the patient underwent systemic chemotherapy. Conclusion: We strongly suggest that clinicians should have a high index of suspicion for malignancies in cases with FUO. Sometimes splenectomy can be the key to solving the problem.