Micromelanomas are not a rarity. However, the clinician should be aware of the fact that the majority of them lack most of the dermoscopic features presented by larger lesions.

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Frequency, morphology, extent and distribution of regression vary according to melanoma thickness and diameter. Lesions with reticular blue regression and light brown areas should undergo surgical excision for the suspicion of MIS. Moreover, the identification of the reticular pattern of blue regression can be considered a significant discriminator and a reliable predictor of MIS.

Endothelia, once thought of as a barrier to the delivery of therapeutics, is now a major target for tissue-specific drug delivery. Tissue-and disease-specific molecular presentations on endothelial cells provide targets for anchoring or internalizing delivery vectors. Porous silicon delivery vectors are phagocytosed by vascular endothelial cells. The rapidity and efficiency of silicon microparticle uptake lead us to delineate the kinetics of internalization. To discriminate between surface-attached and -internalized microparticles, we developed a double fluorescent/FRET flow cytometric approach. The approach relies on quenching of antibody-conjugated fluorescein isothiocyanate covalently attached to the microparticle surface by attachment of a secondary antibody labeled with an acceptor fluorophore, phycoerythrin. The resulting half-time for microparticle internalization was 15.7 min, with confirmation provided by live confocal imaging as well as transmission electron microscopy. (1), and first-stage targeting for multifunctional drug delivery vehicles (2). Distinct features of tumor blood vessels, i.e., vascular zip codes, can function as homing devices for intravascularly administered drug delivery vehicles labeled with appropriate peptides or antibodies (3). As a first step in designing delivery vectors for cancer therapeutics, we have fabricated porous silicon microparticles that are internalized by vascular endothelial cells via phagocytosis and macropinocytosis (4).The distinction between professional and nonprofessional phagocytes is attributed to an array of dedicated phagocytic receptors on the former population that broadens their target range. Nonprofessional phagocytes, such as vascular endothelial cells, are able to internalize large micron-sized particulates (4); however, in contrast to professional phagocytes, serum opsonization of particulates hinders rather than augments internalization. One approach to bypass this obstruction is to bioengineer the surface of drug delivery vehicles to reduce binding to these serum dysopsonins, favoring endothelial uptake of particulates (4).To create delivery vectors with physical characteristics that favor transient interactions with endothelia, we first predicted the optimal size and shape of our silicon particles by mathematical modeling (5). Before applying targeting ligands to our vectors, it is important to first establish techniques to measure binding and uptake of microparticles by endothelial cells. In this report, a comparison of existing methods, as well as a novel method, is presented that characterize the mechanics and kinetics of internalization. Because of the dependence of some of these techniques on fluores-

Background: Melanomas in situ (MIS) are difficult to diagnose, lacking well-established dermoscopic descriptors. Objective: The aim of this study was toimprove the identification of early melanomas describing the variegated dermoscopic features of MIS and their correlation with demographic and clinical aspects. Methods: Dermoscopic images of 114 histologically proven MIS were evaluated by 3 expert dermoscopists and classified into their main dermoscopic patterns. Dermoscopic features were also considered for their correlation with clinical parameters. Results: Eight different dermoscopic subtypes of MIS were identified: reticular grey-blue (27.2%), reticular (21.1%), multicomponent (20.2%), island (10.5%), spitzoid (7%), inverse network (6.1%), ‘net-blue globules’ (5.3%) and globular (2.6%). Clinical characteristics of lesions and patients varied according to the different dermoscopic groups. Conclusion: We hypothesize that the different dermoscopic subgroups of MIS correspond to lesions with a different origin and, possibly, various patterns of growth and a different biological behaviour.