Pathologists often incorporate modifying phrases in their diagnosis to imply varying levels of diagnostic certainty; however, what is implied by the pathologists is not equivalent with what is perceived by the referring physicians and patients. This discordance can have significant implications in management, safety, and cost. We intend to identify lack of consistency in interpretation of modifying phrases by comparing perceived level of certainty by pathologists and non-pathologists, and introduce a standard scheme for reporting uncertainty in pathology reports using the experience with imaging reporting and data systems. In this study, a list of 18 most commonly used modifying phrases in pathology reports was distributed among separate cohorts of pathologists ( N  = 17) and non-pathology clinicians ( N  = 225) as a questionnaire survey, and the participants were asked to assign a certainty level to each phrase. All the participants had practice privileges in Brown University-affiliated teaching hospitals. The survey was completed by 207 participants (17 pathologists, 190 non-pathologists). It reveals a significant discordance between the interpretations of the modifying phrases between the two cohorts, with significant variations in subgroups of non-pathology clinicians. Also there is disagreement between pathologists and other clinicians regarding the causes of miscommunication triggered by pathology reports. Pathologists and non-pathology clinicians should be mindful of the potential sources of misunderstanding of pathology reports and take necessary actions to prevent and clarify the uncertainties. Using a standard scheme for reporting uncertainty in pathology reports is recommended.