Multiple Acrometastases in a Patient with Renal Pelvic Urothelial Cancer

Metastasis may occur in any bone but more commonly occurs in the spine, pelvis, or other axial bones. Metastasis in peripheral bones located distal to the elbow or knee, so-called acrometastasis, is rare. Although the mechanism of acrometastasis development is not completely understood, it is thought to be the result of a massive dissemination of cancer cells; thus the prognosis of patients with acrometastasis is relatively poor. Here, we report the case of renal pelvic cancer with multiple acrometastases in both the upper and lower extremities without axial bone metastasis in a 68-year-old man. After two regimens of chemotherapy, he suffered from pain on his wrist and ankle and swelling and hemorrhage of his toe. He had no axial bone metastasis by CT but was diagnosed with multiple acrometastases by plain radiographs. Radiation therapy and disarticulation of the left big toe at the metacarpal-phalangeal joint were performed and his pain and hemorrhage were successfully controlled. Although acrometastasis from renal pelvic cancer is very rare, we should recognize that acrometastasis might occur which exists outside of the CT scanning field.