Case Report: Thigh anastomotic hemangioma.

Anastomotic hemangioma (AH) is a rare benign vascular tumor primarily occurring in the genitourinary tract; however, only two cases have been reported in the thigh. In this report, a 42-year-old female patient presented to the hospital for examination due to "a subcutaneous mass on the lateral aspect of the left thigh discovered 9 months ago, which has been gradually enlarging." Subsequently, the lump was removed via local surgery. Histological examination reveals: At low magnification, the tumor was situated within the superficial subcutaneous fascia layer, presenting a loose lobular structure. Most of its margins were well - defined, while a small portion displayed expansile infiltrative changes. There were well - differentiated vascular lumens arranged in a communicating or anastomosing pattern, along with pseudopapillary structures. At high magnification, tumor cells were oval or short spindle - shaped, with vacuoles in the cytoplasm that contain red blood cells or homogeneously red - stained glassy globules. Moderate atypia was present, and mitotic activity was frequent, with hot spots averaging approximately 4/mm