Background and objectives: Successful management of maxillofacial lesions follows a specific clinical course: full history and physical exam, radiographic analysis, accurate provisional diagnostic biopsy, and surgical resection enabling accurate final definitive diagnosis. The diagnostic accuracy of incisional biopsies involving various sites in the oral cavity is still not well understood. Additionally, sources of diagnostic error need to be elucidated. We hypothesize that the diagnostic accuracy for incisional biopsies from a series of oral lesions (mucosal, intrabony, glandular, other) will be greater than or equal to 70% based on an earlier study looking at diagnostic accuracy of intrabony jaw lesions (Guthrie et al.).

Methods: This was a retrospective evaluation of 281 incisional biopsies performed at the Massachusetts General Hospital, Department of Oral and Maxillofacial Surgery between 2005 and 2010. Patients included in our study had undergone both incisional tissue biopsy followed by a definitive resection of the lesion. Concordance with the final histologic diagnosis was determined. We reviewed the discordant cases and reasons for discordance were determined and categorized as: sampling error, presence of inflammation, insufficient material and pathologist error.

Results: Eleven percent of the total cases were discordant when comparing the biopsy and final pathology. 70% were intrabony, 20% were mucosal, 6.7% were glandular, and 3.3% were lymphatic. Sixty percent of discordant cases were attributed to sampling error, 23% to pathologist error, 13% to insufficient tissue provided and 3% to inflammatory changes making biopsy diagnosis difficult.

Conclusion: The data collected indicate an 89.3% diagnostic accuracy for incisional biopsies. The majority of the discordant cases were of intrabony origin. Sampling error (biopsy of a non-representative portion of a lesion) was the most common reason for discordance. These tended to be larger, more heterogeneous lesions in which a single biopsy was non-representative. Technique alteration (including more common mapping and multiple site biopsies for large lesions) may improve accuracy.