Figure 2.
Microscopic examination of the tumor revealed a poorly demarcated neoplastic focus that extended beneath the urothelium into the tunica muscularis. The tumor produced lace-like osteoid matrix and/or boney trabeculae. The histopathologic findings were consistent with osteosarcoma in the urinary bladder. Hematoxylin and eosin. Bar = 100 μm.