Fig. 5
From: Undiagnosed synovial hemangioma of the knee: a case report
Histopathological examination revealed that the tumor was composed of numerous blood vessels. a The blood vessels are abnormally enlarged and connected to each other. b A cavernous hemangioma was found in synovial tissue (Hematoxylin and eosin (H&E) stain, original magnification × 40)