Related Experiment Video
Updated: Aug 7, 2026
A Melanoma Patient-Derived Xenograft Model
Published on: May 20, 2019
Usefulness of the staged excision for lentigo maligna and lentigo maligna melanoma: the "square" procedure
T M Johnson1, J T Headington, S R Baker
1University of Michigan Medical Center, Ann Arbor, USA.
Background:
Management of lentigo maligna (LM) and lentigo maligna melanoma (LMM) may present problems because of the characteristic, yet unpredictable, subclinical peripheral and periadnexal extension of atypical junctional melanocytic hyperplasia beyond the visible margins.
Objective:
We used paraffin-embedded (permanent) peripheral vertical section margin control in a staged fashion in the management of LM and LMM.
Methods:
We used a modification of surgical excision in a staged fashion by means of a two-bladed knife with permanent peripheral vertical section margin control.
Results:
This method is technically easy and results in complete histologic evaluation of the peripheral margins without compromising the measurement of tumor thickness of the primary melanoma.
Conclusion:
The use of the "square" procedure, a staged excision with permanent peripheral vertical section margin control, is useful in the management of LM and LMM.
