Easy to see but hard to find

The case of a 46-year-old woman with a rare type of cancer called nonsecretory myeloma illustrates the difficulty of diagnosing some types of cancer. She had all the signs of widely metastatic cancer, but no primary tumor could be found. An oncologist recommended treatment for myeloma even before the diagnosis could be confirmed. But her doctors continued to take biopsies in an effort to establish the diagnosis.