A 69-year-old man presented with back pain over the prior few months and was hospitalized because of bilateral adrenal masses and fracture of the left sixth rib. The mass on the right measured 6.5×3.6×7.0 cm, that on the left 8.1×4.8×6.9 cm, on CT. The final diagnosis was CD5- and CD10-positive primary adrenal diffuse large B-cell lymphoma (PA-DLBCL) with rib involvement. After EPOCH therapy accompanied with rituximab and intrathecal treatment, the tumors decreased dramatically. However, he died due to disease progression 8 months after the diagnosis. The prognosis of CD5- and CD10-positive PA-DLBCL may be very poor even with rituximab-containing chemotherapy.