What could cause a cuff hematoma, cellulitus, abcess after a hysterectomy?

Blood + bacteria: These are among the most common complications after hysterectomy. Cellulitis probably occurs (mild) after most hysterectomies. Abscess is reported at +/-5% of cases, but most see it less frequently in the real world. Usually no avoidable cause is found (other than avoiding surgery). Most important is prompt diagnosis and proper treatment.