Universal in vivo Textural Model for Human Skin based on Optical Coherence Tomograms

Currently, diagnosis of skin diseases is based primarily on visual pattern recognition skills and expertise of the physician observing the lesion. Even though dermatologists are trained to recognize patterns of morphology, it is still a subjective visual assessment. Tools for automated pattern recognition can provide objective information to support clinical decision-making. Noninvasive skin imaging techniques provide complementary information to the clinician. In recent years, optical coherence tomography has become a powerful skin imaging technique. According to specific functional needs, skin architecture varies across different parts of the body, as do the textural characteristics in OCT images. There is, therefore, a critical need to systematically analyze OCT images from different body sites, to identify their significant qualitative and quantitative differences. Sixty-three optical and textural features extracted from OCT images of healthy and diseased skin are analyzed and in conjunction with decision-theoretic approaches used to create computational models of the diseases. We demonstrate that these models provide objective information to the clinician to assist in the diagnosis of abnormalities of cutaneous microstructure, and hence, aid in the determination of treatment. Specifically, we demonstrate the performance of this methodology on differentiating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) from healthy tissue

The Role of in vivo Reflectance Confocal Microscopy in Cutaneous T-cell Lymphoma follow up

Background: Over the last few decades, Reflectance Confocal Microscopy (RCM) has been tested as a diagnostic technique and recently, demonstrates effectiveness to monitor the therapeutic response in melanoma and non-melanoma skin cancer, but it has not been used for follow-up in Cutaneous Lymphoma. This innovative technology allows an in vivo dynamic evaluation of multiple lesions and helps to identify areas of active disease. Moreover, the non-invasive nature of this technique allows repetitive sampling without biopsy collection, causing no further morbidity to patients. Its main advantage is the possibility of risk-free longitudinal monitoring. Objective: Our aim was to evaluate the role of RCM in the follow-up of patients with Mycosis Fungoides (MF). Additionally, to correlate RCM features with clinical and histopathological features before and after treatment. Method: Patients were assessed with RCM on the same site that diagnostic biopsies were performed and re-assessed 6 months after treatment. RCM descriptors were defined by a systematic review. Histopathological correlation and clinical correlation were assessed. Results: A total of 30 patients were assessed by RCM and biopsies were taken in 38 lesions. After 20 to 30 weeks under treatment, 19 lesions were re-assessed by RCM and 12 were re-biopsied. RCM demonstrated good correlation with clinical and histopathological assessments with 4 RCM parameters (epidermotropic lymphocytes, Pautier’s microabscess, interface dermatitis and junctional lymphocytes) achieving an AUC 0.955 (SD: 0.053, p: 0.003). Conclusion: RCM is an excellent tool to assess the response of skin lesion in patients with MF, with excellent correlation with clinic and histological assessment. Keywords: Follow up, Score, Cutaneous T-cell lymphoma, Skin cancer, Reflectance Confocal Microscopy, Mycosis Fungoide

Histometric data obtained by in vivo confocal laser scanning microscopy in patients with systemic sclerosis

BACKGROUND: It would be a benefit if time-saving, non-invasive methods could give hints for diagnosing systemic sclerosis. To investigate the skin of patients with systemic sclerosis using confocal laser scanning microscopy in vivo and to develop histometric parameters to describe characteristic cutaneous changes of systemic sclerosis observed by this new technique, we conducted an exploratory study. MATERIALS AND METHODS: Fifteen patients with systemic sclerosis treated with extracorporal photopheresis were compared with 15 healthy volunteers and 10 patients with other disorders also treated with extracorporal photopheresis. All subjects were investigated using confocal laser scanning microscopy in vivo. RESULTS: Micromorphologic characteristics of skin of patients with systemic sclerosis and measuring parameters for melanisation, epidermal hypotrophy, and fibrosis for dislocation of capillaries by collagen deposits in the papillary dermis were evaluated. An interesting finding was an increased thickness of the tissue in the dermal papillae superior to the first dermal papilla vessel. It was also possible to reproduce characteristic histologic features by confocal laser scanning microscopy in vivo. Histometric parameters for fibrosis and vascular features developed in this study showed significant differences in patients with systemic sclerosis compared to controls. CONCLUSIONS: Although the predominant histopathological features in systemic sclerosis are findings of the reticular dermis and the subcutis, and in histopathological investigation the epidermis seems to remain unaffected by the disease, we have demonstrate some characteristic differences in the epidermis and papillary dermis by confocal laser scanning microscopy in vivo. Some of them have not been described so far. However, to use this technique as a tool for diagnosis and/or staging of systemic sclerosis, further studies are needed investigating the sensitivity and specificity of the histometric parameters developed in this study

Line-field confocal optical coherence tomography: a new tool for the differentiation between nevi and melanomas?

SIMPLE SUMMARY: Typical benign nevi and advanced melanomas can be easily discriminated, but there are still some melanocytic lesions where even experts are not sure about the correct diagnosis and degree of malignity. The high penetration depth of optical coherence tomography (OCT) allows an assessment of tumor thickness of the lesion precisely, but without cellular resolution the differentiation of melanocytic lesions remains difficult. On the other hand, reflectance confocal microscopy (RCM) allows for very good morphological identification of either a nevus or a melanoma, but cannot show the infiltration depth of the lesion because of its low penetration depth. Since the new device of line-field confocal optical coherence tomography (LC-OCT) technically closes the gap between these other two devices, in this study, we wanted to examine if it is possible to differentiate between nevi and melanomas with LC-OCT, and which criteria are the most important for it. ABSTRACT: Until now, the clinical differentiation between a nevus and a melanoma is still challenging in some cases. Line-field confocal optical coherence tomography (LC-OCT) is a new tool with the aim to change that. The aim of the study was to evaluate LC-OCT for the discrimination between nevi and melanomas. A total of 84 melanocytic lesions were examined with LC-OCT and 36 were also imaged with RCM. The observers recorded the diagnoses, and the presence or absence of the 18 most common imaging parameters for melanocytic lesions, nevi, and melanomas in the LC-OCT images. Their confidence in diagnosis and the image quality of LC-OCT and RCM were evaluated. The most useful criteria, the sensitivity and specificity of LC-OCT vs. RCM vs. histology, to differentiate a (dysplastic) nevus from a melanoma were analyzed. Good image quality correlated with better diagnostic performance (Spearman correlation: 0.4). LC-OCT had a 93% sensitivity and 100% specificity compared to RCM (93% sensitivity, 95% specificity) for diagnosing a melanoma (vs. all types of nevi). No difference in performance between RCM and LC-OCT was observed (McNemar’s p value = 1). Both devices falsely diagnosed dysplastic nevi as non-dysplastic (43% sensitivity for dysplastic nevus diagnosis). The most significant criteria for diagnosing a melanoma with LC-OCT were irregular honeycombed patterns (92% occurrence rate; 31.7 odds ratio (OR)), the presence of pagetoid spread (89% occurrence rate; 23.6 OR) and the absence of dermal nests (23% occurrence rate, 0.02 OR). In conclusion LC-OCT is useful for the discrimination between melanomas and nevi

In Vivo Melanoma Cell Morphology Reflects Molecular Signature and Tumor Aggressiveness

Melanoma is the deadliest type of skin cancer, characterized by high cellular heterogeneity which contributes to therapy resistance and unpredictable disease outcome. Recently, by correlating Reflectance-Confocal-Microscopy (RCM) morphology with histopathological type, we identified four distinct melanoma-subtypes: dendritic-cell (DC), round-cell (RC), dermal-nest (DN), and combined-type (CT) melanomas. In the present study, each RCM-melanoma subtype expressed a specific biomolecular profile and biological behavior in vitro. Markers of tumor aggressiveness, including Ki67, MERTK, nestin and stemness markers, were highest in the most invasive CT and DN melanomas, as compared to DC and RC. This was also confirmed in multicellular tumor spheroids. Transcriptomic analysis showed a modulation of cancer progression-associated genes from DC to CT melanomas. The switch from E- to N-cadherin expression proved the epithelial-to-mesenchymal transition from DC to CT subtypes. The DN melanoma was predominantly located in the dermis, as also shown in skin reconstructs. It displayed a unique behavior and a molecular profile associated with a high degree of aggressiveness. Altogether, our results demonstrate that each RCM-melanoma subtype has a distinct biological and gene expression profile, related to tumor aggressiveness, confirming that RCM can be a dependable tool for in vivo detecting different types of melanoma and for early diagnostic screening

<i>In vivo</i> assessment of optical properties of basal cell carcinoma and differentiation of BCC subtypes by high-definition optical coherence tomography

High-definition optical coherence tomography (HD-OCT) features of basal cell carcinoma (BCC) have recently been defined. We assessed in vivo optical properties (IV-OP) of BCC, by HD-OCT. Moreover their critical values for BCC subtype differentiation were determined. The technique of semi-log plot whereby an exponential function becomes linear has been implemented on HD-OCT signals. The relative attenuation factor (µ(raf)) at different skin layers could be assessed.(.) IV-OP of superficial BCC with high diagnostic accuracy (DA) and high negative predictive values (NPV) were (i) decreased µ(raf) in lower part of epidermis and (ii) increased epidermal thickness (E-T). IV-OP of nodular BCC with good to high DA and NPV were (i) less negative µ(raf) in papillary dermis compared to normal adjacent skin and (ii) significantly decreased E-T and papillary dermal thickness (PD-T). In infiltrative BCC (i) high µ(raf) in reticular dermis compared to normal adjacent skin and (ii) presence of peaks and falls in reticular dermis had good DA and high NPV. HD-OCT seems to enable the combination of in vivo morphological analysis of cellular and 3-D micro-architectural structures with IV-OP analysis of BCC. This permits BCC sub-differentiation with higher accuracy than in vivo HD-OCT analysis of morphology alone

Application of Photoacoustic Methods and Confocal Microscopy for Monitoring of Therapeutic Response in Plaque Psoriasis

Psoriasis is prone to relapses and requires long-term therapy that may induce a range of adverse effects; therefore, an efficient and early detection of relapses is desirable. In this study, photoacoustic imaging and confocal laser scanning microscopic (CLSM) methods were investigated for their suitability in psoriasis follow-up examinations. Using a high-resolution photoacoustic system, the vascular structures of 11 psoriatic patients and 6 healthy volunteers were investigated. No differences were detected with respect to the average vessel diameter and vasculature per unit volume in the tissue of healthy volunteers and non-lesional and lesional skin areas of psoriatic patients. By means of CLSM, the diameters of the dermal papillae of 6 volunteers and 6 psoriatic patients were determined. The diameters of the dermal papillae of the healthy volunteers (0.074 +/- 0.006 mm) revealed no significant difference when compared to non-lesional skin areas of psoriatic patients (0.079 +/- 0.005 mm). The results obtained for the lesions in psoriatic patients showed a significant difference (Wilcoxon test, p = 0.028) between the diameters of the dermal papillae of the lesional skin areas 0.114 +/- 0.012 mm) and the non-lesional skin areas (0.079 +/- 0.005 mm). Thus, CLSM can be applied for monitoring psoriasis follow-up examinations

Engineering the Keratinocyte Microenvironment: Harnessing Topography to Direct Cellular Function

Skin wound healing presents a challenging and expensive clinical problem with nearly 20 million wounds requiring intervention leading to an annual cost of more than $8 million. Tissue engineered skin substitutes are valuable not only as a clinical therapy for chronic wounds and severe traumas, but also as in vitro 3D model systems to investigate wound healing and skin pathogenesis. However, these substitutes are limited by a lack of topography at the dermal-epidermal junction (DEJ). In contrast, the native DEJ is characterized by a series of dermal papillae which project upward into the epidermal layer and create physical topographic microniches that support keratinocyte stem cell clustering. In this thesis, we created novel 3D skin model systems to investigate the role of microtopography in regulating keratinocyte function and cell fate using scaffolds containing precisely engineered topographic features. We hypothesized that the microtopography of the DEJ creates distinct keratinocyte microniches that promote epidermal morphogenesis and modulate keratinocyte stem cell clustering which can be harnessed to create a more robust skin substitute that expedites wound closure. Using photolithographic techniques, we created micropatterned DEJ analogs and micropatterned dermal-epidermal regeneration matrices (µDERM) which couple a dermal support matrix to a micropatterned DEJ analog. We found that the incorporation of microtopography into our in vitro skin model resulted in a thicker, more robust epidermal layer. Additionally, we identified three distinct functional keratinocyte niches: the proliferative niche in narrow channels, the synthetic niche in wide channels and the keratinocyte stem cell niche in narrow channels and corner topographies. Ultimately, incorporation of both narrow and wide channels on a single construct allowed us to recreate native keratinocyte stem cell patterning in vitro. These model systems will allow us to investigate the role of cellular microniches in regulating cellular function and epidermal disease pathogenesis as well as to identify topographic cues that enhance the rate of wound healing

Desmoplastic melanoma: a challenge for the oncologist

To evaluate clinical, pathologic and genetic features of desmoplastic melanoma (DM).MATERIALS &amp; METHODS: Analysis of all DM records from 1991 to 2015. RESULTS: The most common location of DMs was the head and neck (69%); median age and follow-up were 60.5 and 7.3 years, respectively. A familial predisposition for DMs and others malignancies was analyzed. Thin Breslow thickness (&lt;4.5 mm) was associated with an intraepidermal component or a previous lentigo maligna, whereas high Breslow thickness (&gt;4.5 mm) was observed in 'pure' DM. CONCLUSION: DM could progress from an early phase, characterized by an intraepidermal component, to late phase, characterized by a dermal nodule. This hypothesis correlates with melanoma genetic and NF1 mutation, which could be an early event in the progression of DM