Background/Objectives: Perineural invasion within keratinocyte cancer is a hallmark of tumour aggression, and a definitive treatment paradigm for this condition remains undetermined. Our aim was to investigate the treatment and outcomes of keratinocyte cancer with incidental perineural invasion within two skin cancer databases to refine treatment protocols. Methods: We retrospectively assessed the Queensland Perineural Invasion Registry for surgery, histopathology, adjuvant radiotherapy and recurrence of keratinocyte cancer five years post-definitive treatment. We also reviewed the Princess Alexandra Hospital Head and Neck clinical perineural invasion database, specifically looking at surgical margins and adjuvant radiotherapy of cutaneous squamous cell carcinoma (cSCC) with incidental perineural invasion in the primary lesion. Results: There was no recurrence at 5 years in the Perineural Invasion Registry. Basal cell carcinoma (BCC) lesions with nerves <0.1 mm were more commonly treated with surgery alone, compared to lesions with nerves ≥0.1 mm which were offered adjuvant radiotherapy. Of the total BCC lesions with incidental perineural invasion, those with perineural margins ≥5 mm and peripheral tumour margins ≥3 mm were predominantly treated with surgery alone. Eighty-nine per cent of cSCC lesions with incidental perineural invasion were treated with surgery and adjuvant radiotherapy. Conclusion: Surgery alone is suitable for BCC lesions with incidental perineural invasion. The majority of BCC lesions achieved ≥5 mm perineural and ≥3 mm peripheral tumour margins. Future research can guide if adjuvant radiation is required for BCC with perineural invasion. The treatment of cSCC with incidental perineural invasion with surgery alone remains undetermined.

This report showed the rates of skin self-examination, sunscreen usage and other sun-protection methods in patients with MPM is higher than in studies of patients with SPM. It also highlighted sex differences in terms of melanoma location for patients with MPM. Further studies to examine the cause of the differences in these forms of protective behaviour could help improve the utilisation of these important preventative measures in all patients.

Melanoma incidence is increasing globally with Australia having the highest incidence in the world. Pregnancy‐associated melanoma is recognized in the published work; however, significant knowledge deficiencies exist. We present the case of a 34‐year‐old woman with dysplastic nevus syndrome who over a 15‐year period developed a total of nine melanomas, with eight clustered around an 18‐month peri‐ to post‐partum period. The first eight lesions were in situ with the ninth lesion invasive. No metastatic disease was observed over the 18‐year follow‐up period. This case identifies the potential sensitivity of a subset of melanomas to pregnancy‐related factors, with particular relevance to the development of lesions in the post‐partum period. We suggest that patients with a history of any documented melanoma risk factors, particularly dysplastic nevus syndrome, require close monitoring especially during pregnancy and early post‐partum.