Final answer:
Immediate nursing intervention is required for bleeding gums in a patient on apixaban prior to surgery, due to increased risk of bleeding complications.
Step-by-step explanation:
When preparing a client for a resection of a leiomyosarcoma of the uterus and noting that apixaban is on the medication list, the assessment finding that requires immediate nursing intervention is bleeding gums. Apixaban is an anticoagulant medication, and bleeding gums may indicate an increased risk of bleeding complications during and after surgery. Immediate intervention and communication with the healthcare provider are necessary to evaluate the risk and consider adjusting the medication regimen to minimize surgical bleeding risk.