A patient diagnosed with stage-four lung cancer and given less than a year to live was relieved to have the correct diagnosis – treatable sarcoidosis. However, he was then concerned about how the misdiagnosis occurred in the first place, risking his health had he gone along with a recommendation for chemotherapy.
After nearly a year of coughing, the patient underwent a CT scan and was diagnosed with sarcoidosis, a treatable lung disease. Shortly after that diagnosis, a lung biopsy found the presence of stage-four lung cancer. The patient was referred to an oncologist, who recommended chemotherapy. Luckily for the patient, the diagnosis didn’t seem right and he sought a second opinion. Although the tissue samples from the initial biopsy tested positive for stage-four lung cancer, additional biopsy results showed that he did not have cancer.
In order to reduce the risk of a diagnosis error like this one occurring in the future, it’s important to identify all the causes that contributed to the issue. We can capture these cause-and-effect relationships in a Cause Map, or visual root cause analysis. The first step in the Cause Mapping process is to capture the impacts to the goals. In this case, there was a potential safety impact to the patient receiving unneeded chemotherapy, which could have potentially caused a worsening of the actual disease from which he was suffering. The patient services goal was impacted by the misdiagnosis and the property and labor goals were both impacted by the potential for unneeded treatment, as can occur with any misdiagnosis.
Once the impacts to the goals have been determined, the next step is to determine the cause and effect relationships by beginning with an impacted goal and asking “Why” questions. The misdiagnosis resulted from the contamination of a biopsy sample sent to the lab to determine the pathology of the disease. The patient’s lab sample was contaminated with stage-four lung cancer from another patient. (DNA testing confirmed the presence of both the patient’s biopsy sample and tissue from a sample of the lung cancer sufferer.) The presence of DNA from both samples indicates that they were cross-contaminated, though the method is still unknown. (The patient with lung cancer was properly diagnosed.) Because the two diseases are pathologically similar, it was not immediately clear that there was a problem with the sample used to make the diagnosis.
Once the patient sought another opinion, it was verified that the first biopsy sample did contain cancer cells. However, another biopsy and blood tests showed he did not have cancer. The original hospital confirmed their diagnosis of cancer even after this information until another biopsy was performed at that facility. Five months after the initial cancer diagnosis was the diagnosis updated to sarcoidosis. The patient filed a complaint with that hospital, as well as the hospital where chemotherapy was recommended, on October 23, 2014.
Once all the causes are determined, solutions can be determined that address the various causes. Because it’s still not clear how the cross-contamination at the lab occurred, an investigation specifically addressing that issue should occur, looking in detail at the specimen handling procedures and adding improvements where necessary to reduce the risk of cross-contamination. (The risk is already very low; the lab has said that it generally handles 70,000 specimens a year and this is the first contamination issue known.)
Additionally, the method for reconsidering diagnoses based on additional testing from alternate providers must be examined. Though the initial misdiagnosis in this case, based on a lab sample that clearly showed the presence of cancer cells, is understandable enough, the ensuing delay in updating the diagnosis despite heavy pushback from the patient is not. Ideally the lessons learned from this case will provide safer and more effective healthcare for everyone.