In Vivo View of a Reclining Demodex Mite in a Milia Cyst.

Demodex folliculorum and Demodex brevis are commonly present on facial skin and frequently noted via Reflectance Confocal Microscopy (RCM) examination. These mites inhabit follicles and are often seen in groups of two or more, although D. brevis is usually found as a solitary mite. When observed through RCM, they are typically present as refractile, round groupings seen on a transverse image plane inside the sebaceous opening, as they are vertically oriented, and their exoskeletons refract under near-infrared light. Inflammation may occur, leading to a variety of skin disorders; nonetheless, these mites are considered to be part of normal skin flora. a 59-year-old woman presented to our dermatology clinic for confocal imaging (Vivascope 3000, Caliber ID, Rochester, NY, USA) of a previously excised skin cancer for margin evaluation. She did not exhibit symptoms of rosacea or active inflammation of the skin. Incidentally, a solitary demodex mite was noted in a milia cyst nearby the scar. The mite appeared to be trapped in the keratin-filled cyst and was positioned horizontally to the image plane such that its entire body was captured in a coronal orientation as a stack. Demodex identification using RCM can provide clinical diagnostic value in the context of rosacea or inflammation; in our case, this solitary mite was thought to be part of the patient's normal skin flora. Demodex are practically ubiquitous on the facial skin of older patients and are frequently noted during RCM examination; however, the orientation of the mite referenced herein is uncommon, allowing for a unique view of its anatomy. The use of RCM to identify demodex may become more routine as access to technology grows.

Reflectance confocal microscopic visualization of melanocytic bodies in the stratum corneum overlying acral lentiginous melanoma.

BACKGROUND: We present a case of RCM evaluation of ALM surgical margins demonstrating intracorneal melanocytic bodies overlying subsequently confirmed melanoma in situ by histopathology. CASE PRESENTATION: A 73-year-old male with a history of acral lentiginous melanoma (ALM) of the right great toe presented to our clinic for evaluation of positive surgical margins. The positive margin was localized for examination and subsequent biopsy with reflectance confocal microscopy (RCM) which allowed targeted re-resection of the area of concern. Three punch biopsies were obtained in the area of concern, which confirmed residual melanoma in situ. Immunostains confirmed the cellular remnants in the stratum corneum were melanocytic. To correlate the intra stratum corneum findings seen with confocal to the histopathology, a 3D rendering of a stack of images was used to demonstrate the location. DISCUSSION: Typically, acral surfaces are challenging to examine with RCM due to the limited ability of light to penetrate thickened stratum corneum; however, we observed unique cellular features with confocal. Scattered hyper-reflective pleomorphic cells consistent with melanocytes were observed in the stratum corneum, although the visualized underlying epidermis appeared normal. Confocal microscopy may aid in diagnosis and management of ALM, especially in the context of positive surgical margins.

Dermoscopy and skin imaging light sources: a comparison and review of spectral power distribution and color consistency.

Significance: Dermoscopes incorporate light, polarizers, and optical magnification into a handheld tool that is commonly used by dermatologists to evaluate skin findings. Diagnostic accuracy is improved when dermoscopes are used, and some major artificial intelligence (AI) projects have been accomplished using dermocopic images. Color rendering consistency and fidelity are crucial for clinical diagnostics, AI, and image processing applications. Aim: With many devices available on the market, our objective was to measure the emission spectra of various dermoscopes, compare them with other light sources, and illustrate variations in reflected colors from images of a reference sample. Approach: A spectrometer measured the spectral power distribution (SPD) produced by four dermoscope models and three alternate light sources, illustrating differences in the emission spectra. Most dermoscopes use light-emitting diodes (LEDs), which are inconsistent when compared with one another. An LED was compared with halogen, xenon-arc, and daylight sources. Images of a micro ColorChecker were acquired from several sources, and three specific colors were selected to compare in CIELAB color space. Color consistency and color fidelity measured by color rendering index (CRI) and TM-30-18 graphical vectors show variation in saturation and chroma fidelity. Results: A marked degree of variation was observed in both the emission and reflected light coming from different dermoscopes and compared with other sources. The same chromophores appeared differently depending on the light source used. Conclusions: A lack of uniform illumination resulted in inconsistent image color and likely impacted metamerism and visibility of skin chromophores in real-world settings. Artificial light in skin examinations, especially LEDs, may present challenges for the visual separation of specific colors. Attention to LEDs SPD may be important, especially as the field increases dependency on machine/computer vision.

Improving dermal level images from reflectance confocal microscopy using wavelet-based transformations and adaptive histogram equalization.

OBJECTIVES: Reflectance confocal microscopy (RCM) generates scalar image data from serial depths in the skin, allowing in vivo examination of cellular features. The maximum imaging depth of RCM is approximately 250 µm, to the papillary dermis, or upper reticular dermis. Frequently, important diagnostic features are present in the dermis, hence improved visualization of deeper levels is advantageous. METHODS: Low contrast and noise in dermal images were improved by employing a combination of wavelet-based transformations and contrast-limited adaptive histogram equalization. RESULTS: Preserved details, noise reduction, increased contrast, and feature enhancement were observed in the resulting processed images. CONCLUSIONS: Complex and combined wavelet-based enhancement approaches for dermal level images yielded reconstructions of higher quality than less sophisticated histogram-based strategies. Image optimization may improve the diagnostic accuracy of RCM, especially for entities with dermal findings.

Impact of graft-versus-lymphoma effect on outcomes after reduced intensity conditioned-alemtuzumab allogeneic haematopoietic stem cell transplantation for patients with mature lymphoid malignancies.

Allogeneic haematopoietic stem cell transplant (allo-HSCT) offers potentially curative therapy for patients with relapsed/refractory lymphoid malignancies. Reduced-intensity conditioning (RIC) with Alemtuzumab reduces transplant-related mortality and graft-versus-host disease (GvHD), but may be associated with increased risk of relapse. With the aim of studying the effect of GVHD and donor lymphocyte infusions (DLI) on relapse, we performed a retrospective study of 288 patients (57% non-Hodgkin lymphoma, 24% Hodgkin lymphoma and 19% chronic lymphocytic leukaemia; 58% were relapsed/refractory) who underwent RIC-Alemtuzumab-HSCT between 2000 and 2012. Median follow-up time for survivors was 64 months. Five-year overall survival, relapse incidence, GvHD/relapse-free survival and non-relapse mortality were 47%, 33%, 37% and 28% respectively. Cumulative incidence of grade II-IV acute and extensive chronic GvHD was 22% and 21% at 100 days and 5 years respectively. On multivariate analysis, presence of GvHD (P = 0·03) and unrelated donor type (P = 0·03) were protective of relapse. 62/288 patients received DLI for either mixed donor chimerism (prophylactic DLI, n = 37) or clinical relapse (therapeutic DLI, n = 25). Prophylactic and therapeutic DLI successfully converted the patient to full or stable mixed donor chimerism in 78% and 56% of patients respectively. These data demonstrate good long-term outcomes and support the concept of the graft-vs-lymphoma effect as a key protective factor against relapse following RIC-Alemtuzumab allo-HSCT for patients with mature lymphoid malignancies.

Cross-polarised and parallel-polarised light: Viewing and photography for examination and documentation of biological materials in medicine and forensics.

Cross-polarisation, with regard to visible light, is a process wherein two polarisers with perpendicular orientation to one another are used on the incident and reflected lights. Under cross-polarised light birefringent structures which are otherwise invisible become apparent. Cross-polarised light eliminates glare and specular highlights, allowing for an unobstructed view of subsurface pathology. Parallel-polarisation occurs when the polarisers are rotated to the same orientation. When cross- or parallel-polarisation is applied to photography, images can be generated which aid in visualisation of surface and subsurface elements. Improved access to equipment and education has the potential to benefit practitioners, researchers, investigators and patients.

Expanded repertoire of RASGRP2 variants responsible for platelet dysfunction and severe bleeding.

Heritable platelet function disorders (PFDs) are genetically heterogeneous and poorly characterized. Pathogenic variants in RASGRP2, which encodes calcium and diacylglycerol-regulated guanine exchange factor I (CalDAG-GEFI), have been reported previously in 3 pedigrees with bleeding and reduced platelet aggregation responses. To better define the phenotype associated with pathogenic RASGRP2 variants, we compared high-throughput sequencing and phenotype data from 2042 cases in pedigrees with unexplained bleeding or platelet disorders to data from 5422 controls. Eleven cases harbored 11 different, previously unreported RASGRP2 variants that were biallelic and likely pathogenic. The variants included 5 high-impact variants predicted to prevent CalDAG-GEFI expression and 6 missense variants affecting the CalDAG-GEFI CDC25 domain, which mediates Rap1 activation during platelet inside-out αIIbß3 signaling. Cases with biallelic RASGRP2 variants had abnormal mucocutaneous, surgical, and dental bleeding from childhood, requiring ≥1 blood or platelet transfusion in 78% of cases. Platelets displayed reduced aggregation in response to adenosine 5'-diphosphate and epinephrine, but variable aggregation defects with other agonists. There were no other consistent clinical or laboratory features. These data enable definition of human CalDAG-GEFI deficiency as a nonsyndromic, recessive PFD associated with a moderate or severe bleeding phenotype and complex defects in platelet aggregation.