Granulocyte colony-stimulating factor (G-CSF)producing tumors are rare and are associated with a poor prognosis when they occur in the lungs and the head and neck region. Positron emission tomography/computed tomography has been reported to show systemic specific accumulation of fluorodeoxyglucose in these cases, but the systemic complications associated with the cytokines produced are not well known. We herein present the case of a G-CSF-producing maxillary sinus squamous cell carcinoma in a 73-year-old Japanese woman with a vertebral fracture and splenomegaly. These findings are known severe adverse events of high-dose recombinant human G-CSF treatment. The aim of the present study was to further discuss the hypothesis that cytokines produced by solid tumors may induce spinal vertebral fracture and splenomegaly.