Progression to bone-marrow carcinomatosis and extraosseous legion during treatment with radium-223 for multiple bone metastases.

A 67-year-old man with metastatic prostate cancer presented with progression to castration-resistant prostate cancer. After sequential therapies with flutamide, estramustine phosphate, docetaxel, enzalutamide, and cabazitaxel for castration-resistant prostate cancer, radium-223 was initiated and continued up to 4 cycles. However, concurrently with radiological and clinical progressions, pancytopenia was observed due to bone-marrow carcinomatosis by prostatic adenocarcinoma. This case suggested that radium-223 should be employed at appropriated timing before appearances of extraosseous and bone-marrow lesions in addition to visceral metastasis.