The successful diagnosis of malignancies depends on precise workflows that support the transfer of adequate and accurate information and tissue samples between the radiologist and pathologist. When the radiologist samples the correct location and the pathologist diagnoses malignant disease in the sample, the patient is typically referred to a cancer care team and the case is reviewed by a hospital-specific cancer committee. Today, radiologists can routinely detect smaller lesions based on radiologic findings such as microcalcifications. This process necessitates a close communication between the specialties to correlate findings. To give an example as to how small these findings can be, one study determined that microcalcifications with an average length of more than 0.41 mm were associated with a malignancy 77 percent of the time, while microcalcifications with an average size of less than 0.41 mm were associated with a malignancy in 29 percent of cases. 7 Smaller lesion size results in greater difficulty in sampling the lesion by both the radiologist and the pathologist. Often, the diagnostic evaluation by radiologists and pathologists occurs in separate departments with widely varying levels of collaboration. 2 This relative isolation increases the risk of radiologic-pathologic discordance. Radiologic-pathologic discordance occurs when the histologic findings do not correlate with or provide sufficient explanation for imaging results. 8
This issue of discordance can relate to either a false positive or false negative diagnosis. As noted above the case of patients with a pathology diagnosis of malignant disease is routinely reviewed by a multidisciplinary cancer committee, and there is a chance that a false positive error may be detected. However, discordance is especially problematic for suspicious radiologic findings with negative pathology results, as the information is not typically further evaluated by a committee or board and the possible health consequences for patients can be significant. These consequences include failure to recognize lesions that were inadequately sampled, false negative results with delayed diagnosis of malignancy, or failure to recognize non-malignant high risk lesions that should prompt additional testing or more aggressive clinical surveillance. Possible causes for discordant results include inadequate sampling of lesions (by either the pathologist or the radiologist), which signifies a need for further examination such as repeat biopsy or surgical excision of lesions 8, or the failure to recognize pre-malignant lesions that require further testing and/or careful monitoring.