Context .- Along with the integration of immunohistochemical markers and molecular techniques into routine practice, addenda in surgical pathology reporting have not only increased in frequency but also evolved to include prognostic and therapeutic information. Because of the lack of uniform practice with respect to issuing addenda, information that can significantly change the diagnosis, prognosis, or treatment plan may be issued as an addendum as opposed to an amendment. Objective .- To audit addenda and identify instances of amendments masquerading as addenda. Design .- All addenda during a 36-month period were reviewed. Each addendum report was classified by accession class, issuing pathologist, subspecialty category, indication for addendum, whether the addendum constituted a change in diagnostic meaning, whether a change in prognosis occurred, and if a change in treatment plan was necessary. Results .- All cytology and autopsy addenda were deemed appropriate. Thirty-three of 5028 (6.5 of 1000) surgical pathology addenda were deemed to have changes: Among the 33 faux addenda, 30 (91%) contained supplemental diagnostic information that would alter patient management and 31 (94%) contained additional information that would change the prognosis from that entailed by the original diagnosis. Conclusions .- Our study demonstrates that not infrequently, surgical pathology addenda contain information that significantly alters the report and thus merit an amendment. Quality monitoring initiatives that evaluate pathologist and departmental performance should assess both addenda and amendments.