Broadly, the tumors were classified as either superficial BCC (sBCC), nodular (nBCC), or micronodular-infiltrative BCC (iBCC) (Fig. 7 and Table 1). Eight morphological-fluorescent criteria were defined for BCC, including presence of fluorescence, clear demarcation, nuclear crowding, clefting, nuclear pleomorphism, palisading, increased nuclear cytoplasmic (N/C) ratio, and the presence of stromal reaction (Fig. 7 and Table 1). Of these, hyperfluorescent aggregates with nuclear crowding (91%), palisading (96%), and nuclear pleomorphism (100%) were identified in all subtypes of BCCs. However, certain criteria were more pronounced than others, which aided in subtyping of BCC. For example, sBCCs appeared poorly defined with hyperfluorescent structures (tumoral nuclei) sparsely distributed along the basal layer of the epidermis with surrounding clefting [Fig. 7 and Table 1]. Stromal reaction and inflammation was less prominent in sBCCs. On the contrary, nBCCs appeared as well-demarcated nodules with crowded hyperfluorescent pleomorphic nuclei, peripheral palisading, and clefting [Fig. 7 and Table 1]. Unlike sBCCs, a significant stromal “starry sky” pattern was associated with nBCCs. Likewise, iBCCs were described as nests and strands of hyperfluorescent pleomorphic nuclei infiltrating dermis with variable nuclear crowding, palisading, and clefting [Fig. 7 and Table 1]. Strong stromal and inflammatory reaction was the most prominent feature of iBCCs [Fig. 7 and Table 1]. FCM criteria, such as clefting, palisading, and “starry sky” stroma, had high specificity for BCC detection and were useful in differentiating BCC nests from the surrounding adnexal structures. The authors stressed the importance of “starry sky” stroma that should initiate a thorough search of BCC foci in the absence of tumor nests. The outcome of the FCM mosaics analysis was later compared with the results of H&E slides. The comparisons were independently evaluated by a dermatopathologist and demonstrated high overall concordance () in classifying BCC subtypes.29 In order to further validate the aforementioned FCM criteria, the same FCM images were also independently evaluated by two dermatologists. These criteria were validated with values greater than 0.7 for most criteria in both independent observers.