[News Space=Reporter seungwon lee] The controversy is spreading as GC Green Cross Medical Foundation, one of the largest contract testing institutions in Korea, caused a major medical accident due to negligence in specimen management.

According to an exclusive report by MBN, the institution misdiagnosed a breast cancer diagnostic specimen, resulting in a partial mastectomy on a woman in her 30s who did not have cancer, resulting in significant medical harm. In response, the Ministry of Health and Welfare decided on August 1, 2025, to revoke the certification for one month, following a final decision by the Specimen Testing Consignment Certification Management Committee.

A misdiagnosis disaster caused by slide labeling errors

The direct cause of this incident was a labeling error during the pathology slide production stage. As a result, a breast cancer sample from another woman who had been tested a day earlier was misdiagnosed, leading to a diagnosis of breast cancer and unnecessary surgery for a healthy woman in her 30s. After the incident was revealed, the GC Green Cross Medical Foundation officially acknowledged the error and issued a formal apology to the victim and the public.

What does decertification mean? Nonpayment of health insurance premiums is tantamount to suspension of business.

This revocation, which followed an on-site investigation by the Korean Society of Pathologists, a committee meeting, and a public opinion collection process, means the Green Cross Medical Foundation will no longer be eligible for reimbursement from the National Health Insurance Service for its interpretation fees. The revocation of a contracted testing institution's certification means that the National Health Insurance Service will no longer recognize the institution's test results, effectively suspending its operations. In fact, three contracted testing institutions that had their certifications revoked in 2021 experienced serious financial crises.

Trust in the medical community is shaken… It's not a simple mistake, but the true face of a systemic failure.

The medical community strongly criticized this incident, calling it a "stain on the history of diagnostic testing." They pointed out that basic safety measures, such as multi-step verification, standardized testing procedures, and personnel training, were not implemented.

A medical and related industry official pointed out that, “This incident is not just a simple mistake, but shows the collapse of the entire contract testing agency system.”

Statistics on the scale of cancer misdiagnosis and breast cancer misdiagnosis in Korea and abroad

According to an analysis by the Korea Consumer Agency, of the 347 cancer-related medical service relief requests filed over the past five years, 131 cases, or 37.8%, were misdiagnoses. Of these, breast cancer misdiagnoses accounted for approximately 12.2% (16 cases), with women being the most affected. Misdiagnosis victims included 13% (17 cases) of patients being diagnosed with cancer when they were not, and, as in the recent Green Cross case, cases of patients being misdiagnosed as cancer when they were not.

Cancer misdiagnosis remains a persistent problem in countries like Japan and the United States. Some studies in the United States have found that the annual cancer misdiagnosis rate (for all cancers) ranges from 10% to 28%, with an unusually high rate of breast cancer misdiagnosis reported during health screenings.

Research results show that more than 70% of international cancer diagnosis errors are due to sample confusion, failure to perform additional tests, and image interpretation errors.

Policy Implications: The Need for Strengthened Certification and Punishment for Contracted Inspectors Is Highlighted

To enhance the effectiveness and severity of penalties under the current system, the Ministry of Health and Welfare is strengthening administrative sanctions, including revocation of certification (for two to four weeks) for a single violation. During the revocation period, all contracted testing cannot be performed, dealing a critical blow to the operation of testing agencies.

The medical community and civil society are calling for the establishment of a "continuous double-check system and automated error prevention system throughout the entire process of entrusting and accepting specimen testing." Furthermore, voices are growing louder calling for systematic compensation for affected patients and regular inspections to prevent similar incidents.