• aminolaevulinic acid;
  • autofluorescence;
  • fluorescence diagnosis;
  • histopathological mapping;
  • Mohs micrographic surgery;
  • protoporphyrin IX


Background  Fluorescence imaging is an attractive diagnostic technique for skin tumour demarcation with potential to move to clinical use. Bispectral fluorescence imaging combines skin autofluorescence with δ-aminolaevulinic acid-induced fluorescence. To evaluate the technique, fluorescence data must be compared with the histopathological extent of the tumour, which is the purpose of the current study.

Objectives  To investigate the agreement between bispectral fluorescence images and the histopathological tumour boundary of ill-defined basal cell carcinomas (BCCs). After fluorescence imaging the tumours were removed using Mohs micrographic surgery (MMS) to obtain histopathological maps of the tumour boundaries.

Methods  Twelve patients with aggressive BCC of mean diameter 16 mm (range 5–32) in the face were included in the study. The patients were subjected to bispectral fluorescence imaging within the 2 months prior to MMS. The fluorescence images and histopathological maps were aligned using image warping.

Results  Five patients (42%) showed good agreement with the histopathological mapping and the remaining seven patients (58%) showed partial agreement. Bispectral investigation combining autofluorescence with protoporphyrin IX (PpIX) fluorescence generally yielded better agreement with the histopathological boundaries of the tumours compared with using only the PpIX fluorescence.

Conclusions  In this preliminary study the fluorescence has been compared with the histopathological tumour boundaries. The result implies that the technique can be applied as a useful tool for indicating tumour boundary of aggressive BCCs. Further refinement is needed to be able to indicate the exact tumour border.