Georgia De'Ambrosis, Brian De'Ambrosis, Duncan Lambie, Jessica Witherspoon, Benedict Panizza, Julie Moore, David Whiteman
Aims: Perineural invasion (PNI) of keratinocyte cancers is a relatively infrequent occurrence, with an estimated Australian prevalence of basal cell carcinoma (BCC) with PNI of 0.36%. More aggressive subtypes of BCC have a greater association with PNI, such as infiltrating, sclerosing and micronodular subtypes. Previous studies have used small sample sizes to analyse the association between BCC subtype and PNI development. We used data from the PNI Study to identify cases of BCCs with PNI, to gain further insight into which subtypes are at higher risk for PNI._x000D_
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Methods: The PNI study used data from the Cancer Alliance Queensland Registry to conduct a retrospective observational study which assessed outcomes of patients with keratinocyte carcinoma exhibiting PNI. We used histopathology reports from 2009–2011 to identify cases of BCCs with PNI. Specifically, we focused on the subtype of BCC, as well as additional features such as number of nerves involved and the depth of PNI._x000D_
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Results: Of the 267 identified keratinocyte tumours exhibiting PNI, 51.31% were BCCs (n = 137). With regards to morphology, 7.3% of the BCCs with PNI were recorded as solid subtype (n = 10), 13.1% of infiltrating subtype (n = 18), 5.8% were of sclerosing/fibrosing/morphoeic subtype (n = 8), 4.4% were of micronodular subtype (n = 6), 67.2% were of mixed subtype (n = 92), 1.5% were recorded as other (n = 2), and 0.7% were basosquamous (n = 1). Of the mixed subtype, 91.3% had infiltrating, sclerosing or micronodular as at least one of the subtypes (n = 84)._x000D_
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Conclusion: The results from our study provide further confirmation that certain subtypes of BCC are at higher risk for developing PNI. The majority of BCCs with PNI were of mixed subtype, and mainly were infiltrating, sclerosing, or both, in nature. Clinicians should be aware of the potential for PNI involvement in patients with aggressive subtypes of BCC, to ensure that there is appropriate management of disease._x000D_
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