One woman had part of her jaw cut away after being wrongly diagnosed with cancer of the mouth.
Engels was now considering reconstructive surgery so she could go swimming without her prosthetic breast: "I want to feel comfortable again."
The Ministry of Health report found the errors occurred during mix-ups with specimens during the laboratory process.
It said the women suffered financially, with one losing her business and others taking extended time off work. Engels had received 80 per cent of her wages and some compensation toward travel.
Two women were disappointed no one discussed options of compensation at all and both are investigating their options. Another, along with Engels, was seeking legal advice.
The report stated: "Adequate compensation would ensure they are at least not financially worse off for undergoing treatment they did not need in the first place."
ACC chief executive Ralph Stewart said the cases were being considered.
"ACC undertakes to ensure the women receive the full benefit of all entitlements available to them under the act."
The report recommended better reporting of errors and more empathy when dealing with patients.
Other recommendations included:
Only one specimen should be handled at a time;
Specimens of the same tissue type should not be handled sequentially;
Robust training and supervision of new staff should be a priority;
Double-checking of specimens and labels by staff at identified critical control points.
Biopsy Solutions pathologist Tony Bierre said the report was good but the recommendations should already be standard practice.
"I am disappointed. I would be horrified to see someone working on two specimens at the same time - that is when errors occur."