[A case of prostate cancer with disseminated carcinomatosis of bone marrow which responded to Zoledronic acid].

A 76-year-old man underwent radical prostatectomy under the diagnosis of stage C prostate cancer (cT3bN0M0, Gleason score 3＋4) in 1999. Endocrine treatment for postoperative biochemical failure started in 2001. He was admitted to our hospital because of general fatigue and multiple bone pain with a prostate specific antigen (PSA) level of 1,141 ng/ml in August 2009. On admission, no metastasis was detected on bone scintigraphy or computed tomography. Bone marrow biopsy was finally performed for the assessment of bone metastasis after PSA further increased to 8,679 ng/ml with the manifestation of severe anemia and thrombocytopenia. The biopsy findings disclosed disseminated carcinomatosis of bone marrow (DCBM). Treatment with Zoledronic acid (ZA) not only mitigated bone pain, but also rapidly improved of PSA and hematological findings. Although the prognosis of a patient with DCBM is generally considered to be very poor, ZA contributed to the improvement for the survival of the patient in the present case.