Manually scanned single fiber optical coherence tomography for skin cancer characterization.

Optical coherence tomography (OCT) is a cross-sectional imaging modality based on low coherence light interferometry. Within dermatology, it has found applications for in vivo diagnostic imaging purposes, as well as to guide Mohs micrographic surgery (MMS), due to its ability to visualize skin morphology up to several millimeters in depth. However, standard OCT probes have a large footprint and capture an extended area of the skin, making it difficult to precisely pinpoint clinically relevant location being imaged. Mohs surgeons stand to benefit from a handheld in vivo imaging device that can accurately trace surgical margins. In this study, we demonstrate the use of a single fiber OCT (sfOCT) instrument. Our imaging system features a miniature common path single fiber probe, and a novel speckle decorrelation technique that generates distortion free 2D images from manual scanning.By manually moving the single-fiber probe across the region of interest, the user can perform a lateral OCT scan while visualizing the location of the probe during data acquisition. Using the sfOCT, we have identified normal skin morphology, qualitatively correlated features of basal cell carcinoma and squamous cell carcinoma with histopathology, and quantified the disruption of the dermo-epidermal junction OCT pattern in skin tumors-each demonstrating the potential of utilizing sfOCT to differentiate tumor from normal skin. Using this imaging tool, a Mohs surgeon can enhance determination of surgical margins for the first stage of MMS, potentially decreasing the time and number of stages required for complete tumor removal.

Langerhans Cells as Morphologic Mimickers of Atypical Melanocytes on Reflectance Confocal Microscopy: A Case Report and Review of the Literature.

Pagetoid spread of melanocytes in the epidermis is a common indicator of melanocytic atypia, both histopathologically and with reflectance confocal microscopy (RCM). Specifically on RCM, large, bright, atypical dendritic and/or roundish cells are characteristic of melanoma. However, intraepidermal Langerhans cells (ILC) create the potential for diagnostic ambiguity on RCM. We describe one case of a pigmented facial lesion that was initially diagnosed as lentigo maligna (LM) due to numerous atypical perifollicular dendritic cells on RCM. Additionally, we present the findings of a literature review for similar reported cases conducted by searching the following terms on PubMed: reflectance confocal microscopy, RCM, lentigo maligna, melanoma, Langerhans cells, dendritic cells, and atypical cells. In our case, the lesion was determined to be a solar lentigo on histopathology. Immunohistochemistry (IHC) with CD1a identified the atypical-appearing cells as ILC, as it did in 54 reported cases of benign lesions (benign melanocytic nevus, Sutton/halo nevus, labial melanotic macule, and solar lentigo) misdiagnosed as malignant on RCM (melanoma, lip melanoma, lentigo maligna, and LM melanoma). According to our case and the literature, both ILC and atypical melanocytes can present with atypical-appearing dendritic and/or roundish cells under RCM. Currently, there is no method to distinguish the two without IHC. Therefore, the presence of pagetoid cells should continue to alert the confocalist of a potential neoplastic process, prompting biopsy, histopathologic diagnosis, and IHC differentiation.

Real-time deep learning assisted skin layer delineation in dermal optical coherence tomography.

We present deep learning assisted optical coherence tomography (OCT) imaging for quantitative tissue characterization and differentiation in dermatology. We utilize a manually scanned single fiber OCT (sfOCT) instrument to acquire OCT images from the skin. The focus of this study is to train a U-Net for automatic skin layer delineation. We demonstrate that U-Net allows quantitative assessment of epidermal thickness automatically. U-Net segmentation achieves high accuracy for epidermal thickness estimation for normal skin and leads to a clear differentiation between normal skin and skin lesions. Our results suggest that a single fiber OCT instrument with AI assisted skin delineation capability has the potential to become a cost-effective tool in clinical dermatology, for diagnosis and tumor margin detection.

Reflectance confocal microscopy evaluation of pigmented lesions on tattooed skin.

The evaluation of pigmented lesions on tattooed skin poses a diagnostic challenge for dermatologists, as a nevus may be partially or completely obscured by tattoo pigment. Because of incidences of melanoma arising from tattooed skin, the current gold standard is to biopsy these lesions. Reflectance confocal microscopy (RCM) is a noninvasive imaging modality used in the diagnosis and management of skin diseases that may allow for diagnosis, while preserving the tattoo design. Retrospective chart review was conducted to identify pigmented lesions on or near tattooed skin that were evaluated with RCM. Confocal characteristics and diagnoses were recorded and analyzed. Nineteen lesions from 15 patients were retrospectively reviewed. Tattoo pigment did not hinder evaluation and diagnosis of pigmented lesions on RCM. About 94.7% of lesions were diagnosed as benign melanocytic nevi by an expert confocal reader. One lesion was confocally diagnosed as melanocytic nevus with atypia but was found to be an inflamed melanocytic nevus on histology. Tattoo pigment particles were differentiated from other hyper-refractile entities by an expert confocal reader based on size, morphology, and clinical correlation. RCM may provide a solution to the diagnostic challenge of pigmented lesions on or near tattooed skin.

Atypical cells on reflectance confocal microscopy may not represent melanoma: A case of axillary pigmented extramammary Paget disease.

Pigmented extramammary Paget disease (PEMPD) is a rare intraepithelial carcinoma which can clinically resemble other pigmented neoplasms. Similarities to melanoma on dermoscopy, histopathology, and reflectance confocal microscopy (RCM) increase the risk of misdiagnosis and, consequently, mismanagement. Here, we describe a case of a 67-year-old African American woman with a large, pigmented axillary patch that exhibited features of melanoma on RCM, guiding the clinician to perform an excisional biopsy. While traditional histopathology resembled melanoma, immunohistochemistry staining was performed and revealed PEMPD. We highlight an uncommon clinical presentation of PEMPD disease and identify morphologic mimickers of melanoma on RCM-as well as differentiating features.

Mobile apps for professional dermatology education: an objective review.

Mobile dermatology applications (apps) created for the purpose of educating students and trainees present convenient supplemental learning opportunities. Before these apps can be widely utilized, there must be a method to assess educational objectives, quality, comprehensiveness of content, evidence-based accuracy, user-friendly design, and potential for bias. Herein, an established rubric was used to conduct a graded review of apps spanning general dermatology, skin cancer, and cosmetics, with an additional emphasis on affordability and accessibility for the user.

The growth of teledermatology: Expanding to reach the underserved.

The regulation of telemedicine in the United States is evolving, with new legislation expanding reimbursement and cross-state licensing capabilities. As telemedicine grows, communities with limited access to traditional dermatologic care may find a solution in teledermatology. A search of the medical literature and online health care law resources published within the past decade was performed to assess the current status of telemedicine availability, health record integration and security, reimbursement policy, and licensure requirements in the United States, with a focus on teledermatology. The majority of states have implemented policies requiring private insurance coverage. Medicaid reimburses some form of telemedicine in all states but restricts which modalities can be used and by which specialties. Medicare places the heaviest limitations on telemedicine coverage. Twenty-four states and Guam are members of the Interstate Medical Licensure Compact (IMLC), and 27 states offer alternative cross-state practice options. With the advent of publicly and privately funded programs, volunteer efforts, and mobile applications, teledermatology is more readily available to rural and underserved communities.

Urologists' estimations of the cost of commonly used disposable devices.

INTRODUCTION: To assess whether urologists are able to accurately estimate the cost of commonly used endourologic disposable devices. MATERIALS AND METHODS: An anonymous questionnaire was presented to resident and attending urologists in one academic healthcare system. Respondents estimated the cost of 15 disposable devices commonly used in ureteroscopy. Twenty-five surgeons (9 resident and 16 attending urologists) participated for a response rate of 96.2%. Respondents' cost estimates were compared to actual institutional costs and considered accurate if the absolute percentage error was within 20%. Additional information obtained included: years in practice, participation in purchasing activities, practice setting, number of ureteroscopy procedures performed monthly, degree of confidence in ability to estimate cost, and the importance of cost in device selection for each respondent. RESULTS: Of 375 total responses, 62 (16.5%) were accurate, 308 (82.1%) were inaccurate, and 5 (1.3%) were unanswered. The mean percentage error (MPE) for all responses was 178.8% (IQR 35.1%-211.4%). Overall, 73% of responses were overestimations and 27% were underestimations. Residents had an MPE of 128.4%, while attending urologists had an MPE of 207.8%. The most inaccurately estimated cost was for an endoscopic y-adapter, while the most accurate estimations were for a 1.5Fr nitinol ureteroscopic stone basket. CONCLUSIONS: Neither attending nor resident urologists are able to accurately estimate the cost of commonly used disposable devices. Improving urologists' understanding of device costs is necessary for improved cost control and a reduction in healthcare expenditures.

Androgen deprivation therapy for the treatment of prostate cancer: a focus on pharmacokinetics.

INTRODUCTION: Medical therapy has undergone many changes as our understanding of prostate cancer cell biology has improved. Androgen deprivation therapy (ADT) remains the mainstay of therapy for metastatic disease. Metastatic castrate-resistant prostate cancer (CRPC) is an important concern since we are unable to stop progression with currently available agents. Areas covered: Pharmacologic ADT is the most commonly used treatment for metastatic prostate cancer. Multiple agents are available for both first-line and second-line use: antiandrogens, estrogens, luteinizing hormone-releasing hormone agonists/antagonists, and CYP17 inhibitors. With adoption of these drugs, it is important to consider their pharmacokinetic and pharmacodynamic properties. Many undergo metabolism through cytochrome P450. Levels may be altered with co-administration of drugs acting as enzyme inhibitors or inducers. Understanding mechanism of action, metabolism, and excretion of these drugs allows clinicians to provide the best therapeutic care while minimizing adverse events. Expert opinion: Many men with metastatic prostate cancer will progress to castration resistance. An understanding of resistance mechanisms at the cellular level has revealed new drug targets with hopes of halting or reversing progression of metastatic disease. Second-line agents, traditionally reserved for CRPC, are being studied in metastatic castrate-sensitive prostate cancer, and may offer practice-changing evidence supporting their use.

Conditional deletion of pejvakin in adult outer hair cells causes progressive hearing loss in mice.

Mutations in the Pejvakin (Pjvk) gene cause autosomal recessive hearing loss DFNB59 with audiological features of auditory neuropathy spectrum disorder (ANSD) or cochlear dysfunction. The precise mechanisms underlying the variable clinical phenotypes of DFNB59 remain unclear. Here, we demonstrate that mice with conditional ablation of the Pjvk gene in all sensory hair cells or only in outer hair cells (OHCs) show similar auditory phenotypes with early-onset profound hearing loss. By contrast, loss of Pjvk in adult OHCs causes a slowly progressive hearing loss associated with OHC degeneration and delayed loss of inner hair cells (IHCs), indicating a primary role for pejvakin in regulating OHC function and survival. Consistent with this model, synaptic transmission at the IHC ribbon synapse is largely unaffected in sirtaki mice that carry a C-terminal deletion mutation in Pjvk. Using the C-terminal domain of pejvakin as bait, we identified in a cochlear cDNA library ROCK2, an effector for the small GTPase Rho, and the scaffold protein IQGAP1, involved in modulating actin dynamics. Both ROCK2 and IQGAP1 associate via their coiled-coil domains with pejvakin. We conclude that pejvakin is required to sustain OHC activity and survival in a cell-autonomous manner likely involving regulation of Rho signaling.