Rapid Lump Examination (RLE) - a bedside 3-dimensional microscopy of tumor specimens

Due to rising skin cancer incidence rates there is an urgent need for a quick, reliable and cost-effective therapy. Previous studies showed that fresh tumor tissue and margins could be directly examined microscopically with high sensitivity and specificity.

Comparing the accuracy of rapid lump examination (RLE) for the detection of basal cell carcinoma (BCC) during micrographic surgery with formalin-fixed paraffin-embedded hematoxylin and eosin (HE)-stained sections.

382 specimens of 118 excised samples with suspected BCC were examined with RLE and compared with formalin-fixed paraffin-embedded HE-stained sections. For RLE, following a standardized 60 sec staining protocol, the fresh tissue samples were observed directly with a stereomicroscope.

For BCC, RLE had a high but insufficient diagnostic accuracy compared to the gold standard of formalin-fixed paraffin-embedded HE-stained sections. The sensitivity was 76 % (95 % CI = [66.18 %; 84.5 %]) and specificity was 91 % (95 % CI = [86.73 %; 93.75 %]).

RLE is a fast and simple technique for microscopically controlled surgery (MCS) of basal cell carcinomas that requires training. The experience of the examiner has a major influence on the results. RLE has great potential to speed up the workflow in Mohs surgery but should be improved in the future.