Multiple cytokine-producing testicular malignant lymphoma with clinical symptoms resembling infectious signs.

We present the case of a 64-year-old male with painful swelling of the bilateral testes and epididymides, high fever, leukocytosis, and an elevated C-reactive protein (CRP) level. This is the first case report of testicular diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS) immunostained for multiple cytokines and their receptors, which clearly demonstrates that tumor cells express multiple cytokines [interleukin-6 (IL-6) and granulocyte colony-stimulating factor (G-CSF)] and their receptors [IL-6 receptor (IL-6R) and G-CSF receptor (G-CSFR)]. The clinical course showed that the reduction in tumor size was accompanied by a corresponding improvement in clinical symptoms and peripheral blood findings. Such clinical investigation may lead clinicians to misdiagnose inflammatory disease rather than neoplastic disease. Recognizing this paraneoplastic phenomenon associated with some cases of testicular DLBCL, NOS is important. In addition, this case suggests that the growth of tumor cells may be promoted through autocrine mechanisms of IL-6 and G-CSF, which are produced by tumor cells. The possibility that these cytokines can be produced by tumor cells and can accelerate tumor proliferation should be considered to be a cause of severe clinical symptoms, an aggressive clinical course, and an indication of the necessity of treatment. Certain cytokines may be used as tumor markers in some cases of DLBCL, NOS.