Lentigo Maligna of the head and neck: A retrospective study assessing surgical excision margins in a South African population

Johann de Wet; Pieter J du Plessis; Johann W Schneider

doi:10.1016/j.jdin.2022.01.008

Lentigo Maligna of the head and neck: A retrospective study assessing surgical excision margins in a South African population

JAAD Int. 2022 Apr 28:7:169-176. doi: 10.1016/j.jdin.2022.01.008. eCollection 2022 Jun.

Authors

Johann de Wet^{1

2}, Pieter J du Plessis^{1

2}, Johann W Schneider³

Affiliations

¹ Division of Dermatology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University and Tygerberg Academic Hospital, Cape Town, South Africa.
² Skinmatters Mohs and Reconstructive Unit, Club Surgical Centre, Hazelwood Pretoria and Summerhill Surgical Centre, Somerset West, South Africa.
³ Division of Anatomical Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University and National Health Laboratory Service, Tygerberg Academic Hospital, Cape Town, South Africa.

Abstract

Background: Lentigo maligna (LM) is a subtype of melanoma in situ that occurs on sun-damaged skin and is associated with significant subclinical extension beyond the clinical margins of the lesion.

Objectives: This study aimed to determine if the standard recommended tumor excision margins for LM are adequate to achieve a 97% clearance rate and if any patient or tumor characteristics warranted wider margins.

Methods: This study is a retrospective chart review of all patients who were diagnosed with LM of the head and neck and treated with staged excision.

Results: The study included 64 patients. With a 6 mm surgical excision margin, only 60.9% of LM were completely excised. A 9 mm margin resulted in complete clearance of 71.9% of LM cases, and a 12 mm margin resulted in complete clearance in 90.6%. A surgical excision margin of 18 mm would have been required to excise 96.7% of tumors completely. Recurrent tumors (P = .01) and tumor size larger than 20 mm were associated with wider surgical excision margins (P = .154).

Conclusion: This study of LM in a South African population corroborates that the standard surgical excision margins recommended by international melanoma guidelines for LM are inadequate to achieve a 97% clearance rate.

Keywords: LM, lentigo maligna; Lentigo maligna; MMS, Mohs Micrographic Surgery; SE, staged excision; WLE, wide local excision; melanoma in situ; staged excision.