Oncology: cancer can be misdiagnosed and an operation can happen followed by a negative pet. can a patient know for sure never had it to begin with?

Shouldnt happen: Surger yis performed when there is a mass or symptomatic lesion. If a scan , a PET, and biopsy confirm a lesion then surgery is perfromed unless under emergency conditions. At surgery the lesion must be confirmed and then the procedure planned for. Bx must reconfirm the pathology. This should be available to the patient post op.