Representation of melanoma depth staging with limited central section sampling: a retrospective simulation study

Area of Science:

• Dermatology
• Oncology
• Pathology

Background:

• Thick melanomas may benefit from retaining the primary lesion during neoadjuvant therapy to increase antigen load and enhance immune response.
• Assessing the accuracy of a single central tissue section versus full serial sectioning is crucial for this approach.

Purpose of the Study:

• To evaluate if a central section of melanoma specimen accurately represents Breslow thickness and ulceration compared to complete serial sectioning.
• To determine the feasibility of using a central section for staging and treatment planning in melanoma.

Main Methods:

• Retrospective analysis of 78 invasive melanomas from 76 patients.
• Digitization of histological slides and measurement of tumor thickness and ulceration across all sections.
• Comparison of measurements from the central section to the overall specimen.

Main Results:

• Median difference in Breslow thickness between central and maximum measurements was <0.2 mm (p < 0.001).
• 82.1% of cases showed thickness within 0.2 mm.
• Ulceration was detected in all 9 positive cases within the central section.
• T-stage remained unchanged in 93.6% of cases.

Conclusions:

• A central melanoma section provides Breslow thickness and T-stage comparable to full serial sectioning in most cases.
• Underestimation of thickness was noted only in thin melanomas.
• Findings support further research into retaining primary melanomas during neoadjuvant therapy to enhance treatment efficacy.