Many of us have had suspicious lesions sampled and biopsied, looking for malignancies. Those biopsies are analyzed and interpreted by pathologists. If cancer is found, the pathologists often stage the cancer depending on the characteristics of it. Then those findings are sent back to the ordering provider to help direct patient care.

Recently, a study looked into how accurate the pathologists were at diagnosing the skin cancer. The study sent each pathologist a number of slides, then sent them the same slides 8 months later. The pathologists’ interpretations were condensed into five classes, and the results were then analyzed.

The study found that most pathologists issued the same diagnoses in both stages of the study on the extremes: most pathologists were consistent in calling cancers in the first and fifth classes of cancer. However, pathologists interpreting the middle classes of cancer were less accurate.

Researchers analyzing the results of the study estimated that nearly 1 in 5 suspected cases of skin cancer are diagnosed as more advanced than they really are, while a similar number are diagnosed as less advanced than they really are. While fortunately few of the biopsies are invasive cancer, this is disconcerting news to anyone dealing with results from such a test. Perhaps in certain situations, a second opinion may be warranted.

You can find the results of the study here:

[Pathologists’ diagnosis of invasive melanoma and melanocytic proliferations: observer accuracy and reproducibility study](http://www.bmj.com/content/357/bmj.j2813)