Eligibility Criteria for Active Ulcerative Pyoderma Gangrenosum in Clinical Trials: A Delphi Consensus on Behalf of the UPGRADE (Understanding Pyoderma Gangrenosum: Review and Assessment of Disease Effects) Group.

At present, there are no standardized guidelines for determining patient eligibility for pyoderma gangrenosum (PG) clinical trials. Thus, we aim to determine which clinical features, histopathological features, or laboratory features should be included in active ulcerative PG clinical trial eligibility criteria for treatment-naïve patients and patients already treated with immunomodulating medications (treatment-exposed patients). This study employed 4 rounds of the Delphi technique. Electronic surveys were administered to 21 international board-certified dermatologists and plastic surgeon PG experts (June 2022-December 2022). Our results demonstrated that for a patient to be eligible for a PG trial, they must meet the following criteria: (i) presence of ulcer(s) with erythematous/violaceous undermining wound borders, (ii) presence of a painful or tender ulcer, (iii) history/presence of rapidly progressing disease, (iv) exclusion of infection and other causes of cutaneous ulceration, (v) biopsy for H&E staining, and (vi) a presence/history of pathergy. These criteria vary in importance for treatment-naïve versus treatment-exposed patients. Given the international cohort, we were unable to facilitate live discussions between rounds. This Delphi consensus study provides a set of specific, standardized eligibility criteria for PG clinical trials, thus addressing one of the main issues hampering progress toward Food and Drug Administration approval of medications for PG.

Increasing productivity with smartphone digital imagery wound measurements and analysis.

OBJECTIVE: The primary aim was to determine the productivity increase using digital imagery for better documentation and analysis. A case series was done in a specialised care centre with patients managed with advanced dressings and using state-of-the-art smartphone technology for documentation to save costs and time. METHOD: Wounds were cleansed and debrided before using the application to photograph, document, measure and analyse the wounds. The smartphone app was oriented parallel to the plane of the wound, where possible, to obtain accurate measurements. A longitudinal study report was generated for each wound and showed the progress of the wound healing until the wound was closed. RESULTS: A sample size of 60 patients consisting of wounds from different locations, and a total of 203 measurements and analyses were conducted over a period of seven months. The wound monitoring app proved to be effective for wound monitoring and required less than two hours' training. A report summary of wounds recorded could also be generated automatically through the dashboard. All 60 patients' cases were automatically recorded, measured and presented into reports for use in clinical analysis. There was a significant time savings (27 hours per day for a specialised care centre with 10 nurses) increase over manual wound documentation and measuring methods. CONCLUSION: The app provided a non-contact, easy to use, reliable and accurate smart wound management solution for clinicians and physicians to track wound healing in patients. The app could also be used by patients and caregivers for home monitoring of their wounds.

Influence of variability in assessment of Breslow thickness, mitotic rate and ulceration among US pathologists interpreting invasive melanoma, for the purpose of AJCC staging.

BACKGROUND: Melanoma staging has depended on depth of invasion (Breslow thickness, BT), mitotic rate (MR) and ulceration. In anticipation of the AJCC's eighth edition, variability in pathologists' assessment of these factors and consequently in tumor staging was assessed. METHODS: One-hundred and fifteen cases of invasive melanoma, established by a consensus panel, were assessed by 187 pathologists. Variation was studied in BT, the detection of mitotic figures, and ulceration. The sources of this variation and its effect on tumor staging are considered. RESULTS: On average, participant assessments closely approached consensus BT. Greater variation was identified in the classification of mitogenicity, which (like ulceration) upstages a T1 melanoma from T1a to T1b in the seventh but not eighth edition. In cases with a T1a diagnosis by the consensus panel, 15.6% of participants identified one or more mitotic figures (indicative of a false positive); and in cases diagnosed asT1b by the consensus panel, 32.0% of participants failed to find mitotic figures (false negative). CONCLUSION: Variability in the staging of T1 melanoma among pathologists when using the AJCC seventh edition criteria is closely related to the detection of mitotic figures, with BT playing a less prominent role. Decreased variability is expected after implementation of the eighth edition.

Assessment of skin lesions produced by focused, tunable, mid-infrared chalcogenide laser radiation.

BACKGROUND: Traditionally, fractional laser treatments are performed with focused laser sources operating at a fixed wavelength. Using a tunable laser in the mid-infrared wavelength range, wavelength-dependent absorption properties on the ablation process and thermal damage formation were assessed with the goal to obtain customizable tissue ablations to provide guidance in finding optimized laser exposure parameters for clinical applications. METHODS: Laser tissue experiments were carried out on full thickness ex vivo human abdominal skin using a mid-infrared tunable chromium-doped zinc selenide/sulfide chalcogenide laser. The laser has two independent channels: a continuous wave (CW) output channel which covers a spectrum ranging from 2.4 µm to 3.0 µm with up to 9.2 W output power, and a pulsed output channel which ranges from 2.35 µm to 2.95 µm. The maximum pulse energy of the pulsed channel goes up to 2.8 mJ at 100 Hz to 1,000 Hz repetition rate with wavelength-dependent pulse durations of 4-7 ns. RESULTS: Total ablation depth, ablation efficiency, and coagulation zone thickness were highly correlated to wavelength, pulse width, and pulse energy. Using the same total radiant exposure at 2.85 µm wavelength resulted in 10-times smaller coagulation zones and 5-times deeper ablation craters for one hundred 6 ns pulses compared to one 100 ms pulse. For a fixed pulse duration of 6 ns and a total radiant exposure of 2.25 kJ/cm2 the ablation depth increased with longer wavelengths. CONCLUSION: The tunable laser system provides a useful research tool to investigate specific laser parameters such as wavelength on lesion shape, ablation depth and thermal tissue damage. It also allows for customization of the characteristics of laser lesions and therefore facilitates the selection of suitable laser parameters for optimized fractional laser treatments. Lasers Surg. Med. 50:961-972, 2018.© 2018 Wiley Periodicals, Inc.

Simulated Wound Assessment Using Digital Planimetry versus Three-Dimensional Cameras: Implications for Clinical Assessment.

BACKGROUND: Clinical management of wounds can benefit from objective measures of response to treatment. Wound surface area and volume are objective measures of wound healing. Using a synthetic wound model, we compare the accuracy and reproducibility of 2 commercially available 3-dimensional (3D) cameras against planimetry and water displacement. METHODS: Twelve ulcers of various sizes and colors were reproduced in modeling clay and cured. Five naive observers used digital planimetry, water displacement, Eykona camera (Fuel 3D, UK), and Silhouette camera (ARANZ, New Zealand) to measure the wounds. RESULTS: When compared with traditional planimetry, wound surface area measurement with Eykona and Silhouette tended to underestimate wounds by 1.7% and 3.7%, respectively. Spearman correlation coefficients were 0.94 (Eykona) and 0.92 (Silhouette). Intraclass correlations for planimetry and the 2 cameras were all 1. Eykona and Silhouette tended to underestimate wound volumes when compared with water displacement by 58% and 23%, respectively. Spearman correlation coefficients were 0.92 (Eykona) and 0.72 (Silhouette). Intraclass correlations for water displacement and the two cameras were all 1. DISCUSSION: Serial accurate objective area measurements are feasible as part of ongoing clinical assessment of wounds. 3D cameras are reliable but have not shown superior accuracy to manual planimetry, and financial concerns and IT integration may limit general clinical usage. Volume measurements of wounds are practicable as part of clinical care.

The clinical importance of air plethysmography in the assessment of chronic venous disease / Importância clínica da pletismografia a ar na avaliação da doença venosa crônica

Abstract Air plethysmography is a non-invasive test that can quantify venous reflux and obstruction by measuring volume changes in the leg. Its findings correlate with clinical and hemodynamic measures. It can quantitatively assess several components of venous hemodynamics: valvular reflux, calf muscle pump function, and venous obstruction. Although clinical uses of air plethysmography have been validated, it is used almost exclusively for medical research. Air plethysmography can be used to assess chronic venous disease, to evaluate improvement after venous surgery, to diagnose acute and past episodes of deep venous thrombosis, to evaluate compression stocking therapy, to study the physiological implications of high-heeled shoes in healthy women, and even to evaluate the probability of ulcer healing.

Resumo A pletismografia a ar é um método não invasivo que pode quantificar refluxo e obstrução venosa medindo alterações no volume das pernas. Seus achados se correlacionam com parâmetros clínicos e hemodinâmicos. Ela pode fornecer informações quantitativas dos diferentes componentes da hemodinâmica venosa: refluxo valvular, função de bomba muscular da panturrilha e obstrução venosa. Apesar de ter seu uso clínico validado, a pletismografia a ar é usada quase que exclusivamente para pesquisa. Ela pode ser usada para avaliar a doença venosa crônica, mensurar o ganho hemodinâmico após cirurgia venosa, diagnosticar trombose venosa profunda atual ou prévia, avaliar os efeitos da elastocompressão, estudar as implicações fisiológicas do uso de salto alto em mulheres e também avaliar a probabilidade de cura de uma úlcera venosa.

A Multimodality Imaging and Software System for Combining an Anatomical and Physiological Assessment of Skin and Underlying Tissue Conditions.

OBJECTIVE: The timely and accurate assessment of skin and underlying tissue is crucial for making informed decisions relating to wound development and existing wounds. The study objective was to determine within- and between-reader agreement of Scout Visual-to-Thermal Overlay (WoundVision LLC, Indianapolis, Indiana) placement (moving the wound edge trace from the visual image onto the wound edge signature of the infrared image). MATERIALS AND METHODS: For establishing within- and between-reader agreement of the Scout Visual-to-Thermal Overlay feature, 5 different readers overlaid a wound edge trace from the visual image and placed it onto the congruent thermal representation of the wound on a thermal image 3 independent times. Forty different wound image pairs were evaluated by each reader. All readers were trained by the same trainer on the operation of the Scout prior to using the software features. The Scout Visual-to-Thermal Overlay feature allows clinicians to use an anatomical measurement of the wound on the visual image (area and perimeter) to extract a congruent physiological measurement of the wound on the thermal image (thermal intensity variation data) by taking the wound edge trace from the visual image and overlaying it onto the corresponding thermal signature of the same wound edge. RESULTS: The results are very similar both within- and between-readers. The coefficient of variation (CV) for the mean PV both within- and between-readers averages less than 1%, 0.89 and 0.77 respectively. When converted into degrees Celsius across all 5 readers and all 3 wound replicates, the average temperature differential is 0.28° C (). The largest difference observed was 0.63° C and the smallest difference observed was 0.04° C. CONCLUSIONS: The Scout software's Visual-to-Thermal Overlay procedure, as implemented in this study, is very precise. This study demonstrates that the thermal signature of wounds may be delineated repeatedly by the same operator and reproducibly by different operators. Thus, clinicians can integrate a criterion standard visual (anatomical) assessment with a congruent physiological assessment to provide them with knowledge relating to the presence or absence of blood flow, perfusion, and metabolic activity in the wound, periwound, and wound site.

Enhancing hair follicle regeneration by nonablative fractional laser: Assessment of irradiation parameters and tissue response.

BACKGROUND AND OBJECTIVE: Identification of methods to enhance anagen entry can be helpful for alopecia. Recently, nonablative laser has been proposed as a potential treatment for alopecia. However, how the laser parameters affect stem cell activity, hair cycles and the associated side effects have not been well characterized. Here we examine the effects of irradiation parameters of 1,550-nm fractional laser on hair cycles. STUDY DESIGN/MATERIALS AND METHODS: The dorsal skin of eight-week-old female C57BL/6 mice with hair follicles in synchronized telogen was shaved and irradiated with a 1,550-nm fractional erbium-glass laser (Fraxel RE:STORE (SR1500) Laser System, Solta Medical, U.S.A.) with varied beam energies (5-35 mJ) and beam densities (500-3500 microthermal zones/cm(2) ). The cutaneous changes were evaluated both grossly and histologically. Hair follicle stem cell activity was detected by BrdU incorporation and changes in gene expression were quantified by real-time PCR. RESULTS: Direct thermal injury to hair follicles could be observed early after irradiation, especially at higher beam energy. Anagen induction in the irradiated skin showed an all-or-non change. Anagen induction and ulcer formation were affected by the combination of beam energy and density. The lowest beam energy of 5 mJ failed to promote anagen entry at all beam densities tested. As beam energy increased from 10 mJ to 35 mJ, we found a decreasing trend of beam density that could induce anagen entry within 7-9 days with activation of hair follicle stem cells. Beam density above the pro-regeneration density could lead to ulcers and scarring followed by anagen entry in adjacent skin. Analysis of inflammatory cytokines, including TNF-α, IL-1ß, and IL-6, revealed that transient moderate inflammation was associated with anagen induction and intense prolonged inflammation preceded ulcer formation. CONCLUSION: To avoid side effects of hair follicle injury and scarring, appropriate combination of beam energy and density is required. Parameters outside the therapeutic window can result in either no anagen promotion or ulcer formation.

The relationship between nailfold capillaroscopic assessment and telangiectasia score with severity of peripheral vascular involvement in systemic sclerosis.

OBJECTIVES: To determine the association of nailfold video-capillaroscopy (NVC) findings and telangiectasia score with digital ulcer (DU) history and severity of peripheral vascular involvement (PVI) in systemic sclerosis (SSc). METHODS: Fifty-nine SSc patients fulfilling Leroy & Medsger criteria were evaluated including telangiectasia score, disease activity and severity scores. NVC was performed according to qualitative (early, active and late patterns) and semi-quantitative assessments. RESULTS: When DU+ and DU- groups were compared; the mean score of capillary number (CN) was 2.0±0.5 vs. 1.4±0.7 (p<0.001), irregularly enlarged capillaries (IEC) was 1.8±0.6 vs. 1.4±0.7 (p<0.05), microangiopathy evolution score (MES) was 2.5±1.5 vs. 1.8±1.0 (p<0.05) and 'early' pattern was significantly less frequent in DU+ patients (1 vs. 9, p=0.016). The frequency of severe-PVI (Medsger severity score of 2-4) was 22% in females (12/54) and 80% in males (4/5). When severe and non-severe groups were compared; the mean score of CN was 2.1±0.4 vs. 1.5±0.7 (p<0.001), MES was 2.8±1.6 vs. 1.8±1.1 (p<0.05) and 'early' pattern was significantly less frequent in patients with severe PVI (0 vs. 9, p=0.049). The mean values of telangiectasia score were similar between groups. CONCLUSIONS: DU history and severe PVI in SSc were associated with capillary loss and microangiopathy. 'Early' NVC pattern was very rare in patients with DU history and was not found in severe PVI. Severe PVI in males was more frequent than females. Telangiectasia scores were not found to be related to PVI. NVC may be a helpful method in the assessment of SSc patients for PVI prognosis, warranting prospective studies.

Histomorphologic assessment and interobserver diagnostic reproducibility of atypical spitzoid melanocytic neoplasms with long-term follow-up.

Predicting clinical behavior of atypical Spitz tumors remains problematic. In this study, we assessed interobserver agreement of diagnosis by 13 expert dermatopathologists for atypical Spitz tumors (n=75). We determined which histomorphologic features were most heavily weighted for their diagnostic significance by the experts and also which histomorphologic features had a statistically significant correlation with clinical outcome. There was a low interobserver agreement among the experts in categorizing lesions as malignant versus nonmalignant (κ=0.30). The histomorphologic features that were given the most diagnostic significance by the experts were: consumption of the epidermis, atypical mitoses, high-grade cytologic atypia, and mitotic rate. Conversely, the histomorphologic features that most correlated with disease progression were: frequent mitoses, deep mitoses, asymmetry, high-grade cytologic atypia, and ulceration. The presence and/or pattern of pagetoid spread, consumption of the epidermis, and lymphoid aggregates demonstrated no association with clinical behavior. The results support the assertion that there is a lack of consensus in the assessment of atypical Spitz tumors by expert dermatopathologists. Importantly, many features used to distinguish conventional melanoma from nevi were not useful in predicting the behavior of atypical Spitz tumors. This study may provide some guidance regarding histologic assessment of these enigmatic tumors.

Functional impairment of systemic scleroderma patients with digital ulcerations: results from the DUO Registry.

OBJECTIVES: Digital ulcers (DUs) are frequent manifestations of systemic scleroderma (SSc). This study assessed functional limitations due to DUs among patients enrolled in the Digital Ulcer Outcome (DUO) Registry, an international, multicentre, observational registry of SSc patients with DU disease. METHODS: Patients completed at enrolment a DU-specific functional assessment questionnaire with a 1-month recall period, measuring impairment in work and daily activities, and hours of help needed from others. Physician-reported clinical parameters were used to describe the population. For patients who completed at least part of the questionnaire, descriptive analyses were performed for overall results, and stratified by number of DUs at enrolment. RESULTS: This study included 2327 patients who completed at least part of the questionnaire. For patients with 0, 1-2, and ≥3 DUs at enrolment, mean overall work impairment during the prior month among employed/self-employed patients was 28%, 42%, and 48%, respectively. Across all included patients, ability to perform daily activities was impaired on average by 35%, 54%, and 63%, respectively. Patients required a mean of 2.0, 8.7, and 8.8 hours of paid help and 17.0, 35.9, and 63.7 hours of unpaid help, respectively, due to DUs in the prior month. Patients with DUs had more complications and medication use than patients with no DUs. CONCLUSIONS: With increasing number of DUs, SSc patients reported more impairment in work and daily activities and required more support from others.

US skin disease assessment: ulcer and wound care.

Chronic ulcers are a growing cause of patient morbidity and contribute significantly to the cost of health care in the United States. The most common etiologies of chronic ulcers include venous leg ulcers (VLUs), pressure ulcers (PrUs), diabetic neuropathic foot ulcers (DFUs), and leg ulcers of arterial insufficiency. Chronic wounds account for an estimated $6 to $15 billion annually in US health care costs; however, it is difficult to get accurate measurements on this, because these patients are often seen in a variety of settings or simply fail to access the health care system.

Bates-Jensen wound assessment tool: pictorial guide validation project.

PURPOSE: A group of 3 WOC nurses and a nurse researcher, in partnership with the author of the Bates Wound Assessment Tool (BWAT), sought to validate wound photographs depicting each characteristic of the instrument. INSTRUMENT: The BWAT contains 13 items that assess wound size, depth, edges, undermining, necrotic tissue type, amount of necrotic, granulation and epithelialization tissue, exudate type and amount, surrounding skin color, edema, and induration. These are rated using a modified Likert scale; a score of 1 indicates the healthiest and 5 indicates the most unhealthy attribute for each characteristic. In 2001, the PSST was revised and renamed the Bates-Jensen Wound Assessment Tool to reflect the global use of the tool with wound types beyond pressure ulcers. METHODS: Phase 1 involved the selection of digitalized wound photographs for 11 of the BWAT wound characteristics by the researchers. The photographs needed to be of high resolution and good quality for eventual publication and validated by the original BWAT author as being representative of the intended characteristic. In phase 2, a face-to-face validation exercise was completed to include, edit, or exclude these photographs. Corrections were made; additional photographs were obtained for the remaining characteristics and to replace those not validated. Phase 3 involved an electronic survey that achieved validation online. PARTICIPANTS: Phase 2 participants consisted of 15 WOC nurses with a mean of 11.5 years of experience with wounds. Phase 3 had 8 WOC nurses and 1 master's prepared wound care specialist, with approximately 10 years of experience. One third of participants in each phase were familiar with the BWAT. In a separate exercise to rate photographs that would be used for testing the implementation of the pictorial guide, 7 WOC nurses and 2 RNs who used the BWAT regularly and 2 researchers participated in a face-to-face discussion. RESULTS: A total of 214 photographs were reviewed in this study. Seventy-three percent (n = 55) of the photographs for the pictorial guide were endorsed in phase 2, and 100% (n = 53) in phase 3 to demonstrate the 65 BWAT characteristics. In addition, photographs that could be used for a competency exercise and for pre- and posttests were also rated by the panels. CONCLUSIONS: The photographic content of the BWAT pictorial guide has been validated by a small group of wound care experts. The purpose of the exercise was to create a visual learning aid to enhance the education around wound assessment and as a resource for nurses in practice. Now published in a pocket guide format, it is a standardized way to teach BWAT wound assessment skills in a consistent format.

Bioimaging assessment and effect of skin wound healing using bone-marrow-derived mesenchymal stromal cells with the artificial dermis in diabetic rats.

We investigate the relationship between the fate and healing effect of transplanted mesenchymal stromal cells (MSCs) in a rat diabetic skin wound model. Rats are treated with streptozotocin to induce diabetic conditions. A full-thickness skin defect is surgically made on the head of diabetic rats, and covered with an artificial dermis impregnated with either bone marrow cells (BMCs) or bone-marrow-derived MSCs from firefly luciferase (luc) transgenic (Tg) rats. Wound healing is evaluated using planimetry and immunohistochemistry, and the fate of transplanted MSCs is determined using in-vivo luminescent imaging. The diabetic wound treated with MSCs-impregnated artificial dermis is significantly smaller than that treated with artificial dermis alone at 1 week postoperation. Photons of luc+ MSCs are detected at the transplanted site during healing (3 weeks), whereas those of luc+ MSCs are depleted only after 1 week postimplantation. Immunohistochemistry at the healing site treated with MSCs demonstrates that CD31+ vessels increase with expression of vascular endothelial growth factor, suggesting that MSCs accelerate angiogenesis. These findings suggest that transplanted MSCs could be retained at wound sites during the healing process in a diabetic rat model, and subsequently promote wound healing through angiogenesis.

Multitiered health assessment of Atlantic menhaden in the Pamlico River, North Carolina.

During the fall of 2001 and 2002, Atlantic menhaden Brevoortia tyrannus were collected from several creeks in the Pamlico River, North Carolina, to investigate recent fish kills and ulcerative skin lesions. High skin lesion prevalence (>50%) was associated with the Atlantic menhaden kills in fall 2001, whereas there were no fish kills in fall 2002 and skin lesion prevalence was lower (< or =50%). Indicators of tissue damage (histopathological analyses of gills, heart, liver, intestine, and anterior kidney), body condition (liver somatic index), and immune status (transforming growth factor-beta [TGF-beta] messenger RNA [mRNA] production, hematology, plasma chemistry, and splenosomatic index) were compared between Atlantic menhaden with and without ulcerative skin lesions in fall. Atlantic menhaden with ulcerative skin lesions had significantly higher liver somatic indices, neutrophil and monocyte percentages, and splenic mononuclear cell TGF-beta mRNA levels than did fish without lesions. Hematocrit values, plasma protein, and Ca concentrations were significantly lower in fish with ulcerative skin lesions than in those without. The indicators used in this study at multiple levels of biological organization have provided valuable baseline data for understanding the health status of lesioned and nonlesioned Atlantic menhaden in the Pamlico River.

Clinical assessment of infection in nonhealing ulcers analyzed by latent class analysis.

The distinction between bacterial colonization and infection relies on clinical judgement. Determining sensitivity and specificity of this judgement are problematic as no gold standard exists. Six specialists in wound management independently assessed 120 nonhealing chronic wounds. Sixty-five (54.2%) patients had venous ulcer, 18 (15%) arterial ulcers, 15 (12.5%) ulcerative pyoderma gangraenosum, 12 (10%) neuropathic or pressure ulcers, six (5%) vasculitis ulcers, and four patients had ulcers caused by a primary or metastatic cancer disease. Unrestricted latent class analysis was used for determining sensitivity and specificity in the observer's assessment of hypergranulation, redness, and overall impression of infection. Interrater agreement among observers was determined by restricted latent class analysis. The observers used the diagnoses (redness, hypergranulation, and overall impression of infection with different frequencies (p<0.001, Cochrane's Q test). A two latent class model fitted data. Sensitivity for hypergranulation ranged from 3 to 82%, for redness from 34 to 91% and for overall impression of infection from 37 to 90%. None of the observers were interchangeable. These results indicate that clinical assessment of chronic wounds for the presence of infection are difficult tasks accompanied by great variability and low reliability.

Assessment of the role of sentinel lymph node biopsy for primary cutaneous desmoplastic melanoma.

BACKGROUND: The role of sentinel lymph node biopsy (SLNB) in the treatment of desmoplastic melanoma (DM) remains undefined. The purpose of this study was to evaluate the use of SLNB for DM. METHODS: In all, 1850 patients with cutaneous melanoma underwent wide local excision and SLNB. Patients with DM were identified and stratified as 'pure' DM or 'mixed' DM (i.e., DM associated with at least one other common histologic subtype). RESULTS: Of the 1850 patients, 65 (3.5%) had DM. Of these, 46 (70.8%) had pure DM and 19 (29.2%) had mixed DM. Patients with pure DM had a median tumor thickness of 3.5 mm and 6.5% were ulcerated. Compared with patients with pure DM, patients with either mixed DM or non-DM (n = 1785) had thinner primary tumors (median, 1.7 mm and 1.5 mm, respectively, each P < 0.001 vs. pure DM) that were more likely to be ulcerated (27.7% and 21.3%, respectively, each P < 0.05 vs. pure DM). Although the incidence of a positive SLN was similar in patients with mixed DM (15.8%) and non-DM (17.5%), patients with pure DM were less likely to have a positive SLN (2.2%) (each P < 0.01 vs. non-DM and mixed DM). At a median follow-up of 2.9 years, no patient with pure DM had recurred. CONCLUSIONS: Despite having thicker primary tumors, patients with pure DM have a lower incidence of positive SLNs compared with patients with non-DM. Whereas the treatment approach for patients with mixed DM should be similar to that of other melanoma patients, patients with pure DM are unlikely to have metastatic disease in regional lymph nodes and SLNB may not be warranted.