Mohs micrographic surgery histopathology concordance

Area of Science:

• Dermatology
• Surgical Pathology
• Oncology

Background:

• Mohs micrographic surgery (MMS) offers low recurrence rates and tissue sparing.
• Accurate frozen section interpretation by the MMS surgeon is critical for successful outcomes.
• Ensuring diagnostic accuracy is paramount in Mohs surgery procedures.

Purpose of the Study:

• To evaluate the agreement between dermatopathologists and MMS surgeons in diagnosing cutaneous malignancies.
• To quantify concordance rates in frozen section interpretation within the MMS setting.
• To identify specific areas of diagnostic disagreement.

Main Methods:

• Retrospective analysis of 1156 frozen sections over a 10-year period.
• Utilized a randomized, blinded quality assurance protocol.
• Compared interpretations from 5 dermatopathologists against 3 MMS surgeons and 5 fellows.

Main Results:

• Overall concordance rate between MMS surgeons and dermatopathologists was 99.7%.
• Only 32 out of 1156 slides (2.8%) showed disagreement.
• Discrepancies were predominantly associated with the interpretation of intraepidermal neoplasia (in situ malignancy).

Conclusions:

• High statistical concordance exists between MMS surgeons and dermatopathologists in interpreting frozen sections during Mohs surgery.
• The primary source of discordance relates to the diagnosis of in situ malignancies.
• Findings support the reliability of frozen section interpretation in the MMS setting at a single institution.