The impact of haematoxylin-eosin staining and immunohistochemistry of lentigo maligna and lentigo maligna melanoma margins on local recurrence.

Background: Local recurrence of lentigo maligna melanoma (LMM) and lentigo maligna (LM) continue to be challenging following surgical treatment and aftercare.

Objectives: To investigate haematoxylin-eosin staining and immunohistochemistry of the tumour margins of LM and LMM and evaluate the impact of these data on local recurrence.

Materials & Methods: In total, 489 tumours were included in this retrospective single-centre study, among them 199 (40.7%) LMs and 290 (59.3%) LMMs. All tumours were excised using micrographiccontrolled surgery. Additional immunohistochemistry staining of the tumour margins was performed in 35 specimens (7.2%).

Results: Based on haematoxylin-eosin staining alone, 82/454 tumours (18.1%) were shown to develop local recurrence compared to 3/35 tumours (8.6%) when additional immunohistochemistry was performed.

Conclusion: Following micrographic-controlled surgery, the additional use of immunohistochemistry of tumour margins of LM/LMM reduced the risk of local recurrence, although this was not statistically significant.