Histologic observation of bone resorption in the mice IV inoculated with KPMM2 cells. (A, B) Tumor-bearing mouse. (C) Normal mouse. (A) Osteolytic lesions and osteoclastic cells (arrow) were observed in cortical bone surface. Bone marrow was occupied by tumor cells. (B) The end of femur. Spongy bone completely disappeared in IV transplanted mouse. (C) Spongy bone (arrow) was observed in normal mouse.