Processing Adipose-Rich Mohs Samples: A Comparative Study of Effectiveness of Pretreatment With Liquid Nitrogen...

Area of Science:

• Dermatology
• Pathology
• Surgical Techniques

Background:

• Processing adipose-rich Mohs micrographic surgery (MMS) specimens presents challenges for complete margin evaluation.
• Existing methods for freezing these specimens have not been optimized or compared.
• High-adipose content can lead to suboptimal frozen section quality.

Purpose of the Study:

• To compare the frozen section quality of high-adipose MMS specimens using different cooling methods.
• To evaluate the efficacy of 1,1,1,2-tetrafluoroethane (TFE) and liquid nitrogen (LN2) as adjuncts to standard processing.
• To determine if LN2 or TFE pretreatment improves slide quality over no additional cooling.

Main Methods:

• Three sections were obtained from 24 adipose-rich MMS specimens.
• Sections were treated with no cooling (control), TFE spray, or LN2 spray.
• Blinded raters assessed slide quality based on margin completeness, nuclear clearing, folding, holes, and artifacts.

Main Results:

• Liquid nitrogen (LN2) pretreatment yielded significantly higher quality slides (19/24) compared to TFE (1/24) and control (0/24) (P < 0.001).
• LN2 spray effectively addressed challenges associated with processing thick, high-adipose specimens.
• No additional cooling or TFE pretreatment resulted in poor slide quality.

Conclusions:

• Adjunctive use of LN2 spray before tissue embedding significantly improves frozen section quality for adipose-rich MMS specimens.
• LN2 pretreatment circumvents processing challenges, facilitating high-quality frozen slides during Mohs surgery.
• This technique enhances the reliability of margin evaluation in difficult-to-process specimens.