07 July 2012
In vivo reflectance confocal microscopy of shave biopsy wounds: feasibility of intraoperative mapping of cancer margins
Scope A., Mahmood U., Gareau D.S., Kenkre M., Lieb J.A., Nehal K., Rajadhyaksha M.
Background Reflectance confocal microscopy (RCM) images skin at cellular resolution
and has shown utility for the diagnosis of nonmelanoma skin cancer in vivo.
Topical application of aluminium chloride (AlCl3) enhances contrast in RCM
images by brightening nuclei.
Objectives To investigate feasibility of RCM imaging of shave biopsy wounds using
AlCl3 as a contrast agent.
Methods AlCl3 staining was optimized, in terms of concentration vs. immersion
time, on excised tissue ex vivo. RCM imaging protocol was tested in patients
undergoing shave biopsies. The RCM images were retrospectively analysed and
compared with the corresponding histopathology.
Results For 35% AlCl3, routinely used for haemostasis in clinic, minimum immersion
time was determined to be 1 min. We identified three consistent patterns of
margins on RCM mosaic images by varying depth: epidermal margins, peripheral
dermal margins, and deep dermal margins. Tumour islands of basal cell
carcinoma were identified at peripheral or deep dermal margins, correlating on
histopathology with aggregates of neoplastic basaloid cells. Atypical cobblestone
or honeycomb patterns were identified at the epidermal margins in squamous
cell carcinomas, correlating with a proliferation of atypical keratinocytes extending
to biopsy margins.