Rapid screening of cancer margins in tissue with multimodal confocal microscopy

Background: Complete and accurate excision of cancer is guided by the examination of

histopathology. However, preparation of histopathology is labor intensive and slow,

leading to insufficient sampling of tissue and incomplete and/or inaccurate excision of

margins. We demonstrate the potential utility of multimodal confocal mosaicing microscopy

for rapid screening of cancer margins, directly in fresh surgical excisions, without the

need for conventional embedding, sectioning, or processing.

Materials and methods: A multimodal confocal mosaicing microscope was developed to

image basal cell carcinoma margins in surgical skin excisions, with the resolution that

shows nuclear detail. Multimodal contrast is with fluorescence for imaging nuclei and

reflectance for cellular cytoplasm and dermal collagen. Thirty-five excisions of basal cell

carcinomas from Mohs surgery were imaged, and the mosaics analyzed by comparison

with the corresponding frozen pathology.

Results: Confocal mosaics are produced in about 9 min, displaying tissue in fields of view of

12mm with 2 magnification. A digital staining algorithm transforms black and white

contrast to purple and pink, which simulates the appearance of standard histopathology.

Mosaicing enables rapid digital screening, which mimics the examination of

histopathology.

Conclusions: Multimodal confocal mosaicing microscopy offers a technology platform to

potentially enable real-time pathology at the bedside. The imaging may serve as an adjunct

to conventional histopathology to expedite screening of margins and guide surgery toward

more complete and accurate excision of cancer.