Flash freezing of Mohs micrographic surgery tissue can minimize freeze artifact and speed slide preparation

Quenby L Erickson1, Trishina Clark, Kassandra Larson

  • 1Department of Dermatology, Mohs and Dermasurgery Unit, MD Anderson Cancer Center, Houston, Texas, USA.

Abstract

Insights

Flash freezing Mohs tissue in a histobath significantly reduces freezing time and improves tissue quality compared to traditional cryostat freezing. This method enhances slide turnaround time and minimizes artifacts for better diagnostic accuracy.

Area of Science:

  • Dermatology
  • Pathology
  • Surgical Techniques

Background:

  • Traditional Mohs surgery uses cryostat freezing, which can cause delays and artifacts.
  • Flash freezing is a technique used in general pathology to speed up processing and improve histology.
  • Minimizing ice crystal formation is key to enhancing tissue quality.

Purpose of the Study:

  • To compare flash freezing with traditional cryostat freezing for Mohs micrographic surgery specimens.
  • To evaluate the impact on slide turnaround time (TAT) and tissue histology quality.

Main Methods:

  • A pilot quality improvement study compared flash freezing in an isopentane histobath (-56 to -62°C) with standard cryostat freezing (-27 to -30°C).
  • Mohs tissue layers were divided, with one half flash frozen and the other cryostat frozen.

Main Results:

  • Flash freezing averaged 22 seconds, significantly faster than the cryostat's 144 seconds.
  • 90% of tissue sets frozen in the histobath were easier to section smoothly.
  • Physicians preferred the histology of flash-frozen specimens 65-85% of the time.

Conclusions:

  • Flash freezing in a histobath expedites specimen preparation for cryotomy, reducing slide TAT.
  • This method enhances tissue histology quality and minimizes freeze artifact compared to traditional cryostat freezing.