Fig. 4.

LOT measurements of benign melanocytic nevi. (a),(d) White light images of Compound and Junctional nevi respectively. (b),(e) Raw LOT image (source-detector separation = 0.25mm) showing reference region (white box) and measurement region (red or blue box) for differential contrast calculation. (c),(f) Representative hematoxylin and eosin (H&E) histopathology images of junctional and compound nevi (40X) [28]. Scale bars approximately 100 microns. Arrowheads demonstrate location of melanocytes. Note that melanocytes in the compound nevus extend deep into the dermis, while melanocytes in the junctional nevus are limited to a thin region at the dermal – epidermal junction. (g), (h) LOT differential contrast and plot of fit parameters. Error bars show standard deviations of 15 repeated scans. RMS error of fit was 0.0096 and 0.0266 for the compound and junctional cases, respectively. Fit results are consistent with the compound nevus being substantially thicker than the junctional nevus, with both lesions being superficial.