[en] In a 39-year-old man with IgD myeloma, bone scanning with Tc-99m diphosphonate was false negative, despite the presence of punched out lesions of the ischium, pubis, and femur on x-ray. It is suggested in the literature that false negative scanning and roentgenographically demonstrable punched out lesions would be unusual in the case of bone metastasis of malignant tumor. The finding may thus implicate the value of combined x-ray and bone scanning in the differentiation between myeloma and bone metastasis of malignant tumor. (Namekawa, K.)