SOX10 commonly stains scar in Mohs sections.

Area of Science:

• Dermatopathology
• Surgical Pathology
• Immunohistochemistry

Background:

• Sox10 immunostaining is a key diagnostic tool for melanocytic lesions and margin evaluation.
• It was previously believed that Sox10 did not stain fibrohistiocytic processes, aiding in distinguishing desmoplastic melanoma from scar.
• Emerging evidence suggests Sox10 may be less specific than initially thought, particularly in certain tissue preparations.

Purpose of the Study:

• To investigate the specificity of Sox10 immunostaining in Mohs frozen sections.
• To evaluate the potential for Sox10 to stain non-melanoma tissues, specifically scar.
• To inform Mohs practitioners about potential diagnostic pitfalls.

Main Methods:

• Analysis of Sox10 immunostaining patterns on Mohs frozen sections.
• Comparison of staining in melanocytic lesions versus scar tissue.
• Review of immunohistochemistry protocols for frozen sections.

Main Results:

• Sox10 staining was frequently observed in scar tissue within Mohs sections.
• This staining was often strong and fractional, mimicking melanoma.
• Formalin-fixed sections showed less specificity than previously assumed.

Conclusions:

• Sox10 immunostaining on Mohs frozen sections can exhibit fractional staining of scar.
• This finding necessitates caution to prevent overdiagnosis of desmoplastic melanoma.
• Awareness of Sox10's potential to stain scar is crucial for accurate Mohs surgery diagnosis.