The importance of reviewing pathology specimens before Mohs surgery.

Background: The review of outside biopsy slides before performing surgery is the standard of care in many surgical specialties. Previous studies have shown high discrepancy rates between the original and second-opinion diagnoses. The frequency with which this practice changes the diagnosis and management of patients undergoing Mohs surgery is undocumented in the literature. It is standard practice at our institution to review all outside biopsy slides before Mohs surgery.

Objective: To investigate how often review of outside biopsies by an internal dermatopathologist changes patients' initial referral diagnosis and subsequent management.

Methods & Materials: This is a retrospective review of all patients referred to Mohs surgery from January 2003 through March 2007. The number of cases in which the diagnosis changed and how this change affected management were recorded.

Results: Seventy-four of 3,345 (2.2%) cases were identified in which the diagnosis changed after review of the biopsy slides. Management was affected in the majority (61%) of cases. Board-certified dermatopathologists originally read nearly half of the biopsies.

Conclusion: Review of outside biopsy slides before surgery can change the diagnosis in a large proportion of patients, with a resulting change in management. This quality-assurance practice may improve patient care.