Citations

AbstractBackgroundThe International Dermoscopy Society (IDS) recently released a set of five basic dermoscopic parameters (vessels, scales, follicular findings, “other structures,” and specific clues) encompassing a total of 31 subitems to standardize the use of dermoscopy in non‐neoplastic dermatoses, yet they have been developed taking into account Caucasian/Asian skin, with consequent possible limitations if used in dark skin.ObjectivesTo validate the abovementioned criteria for the use in dark‐skinned patients (phototypes IV–VI) through an expert consensus.MethodsThe two‐round Delphi method was adopted, with an iterative process consisting of two rounds of email questionnaires. Potential panelists were recruited via e‐mail from all over the world based on their expertise on dermoscopy of non‐neoplastic dermatoses in skin of color.ResultsTwenty‐two panelists took part in the validation process. All of the five originally proposed parameters and subitems reached agreement during the first round, aside from “follicular red dots.” Additionally, during round 1, five new subitems were proposed (perifollicular scales distribution, follicular openings obliteration, broken hairs, eccrine pigmentation, and eccrine ostia obliteration), along with the possibility to change the denomination of parameter 3 (from “follicular findings” to “follicular/eccrine findings”) and split it into two subparameters (“follicular findings” and “eccrine findings”). All such proposals reached agreement during the second round and therefore were included in the final list, for a total of 37 items.ConclusionsAlthough nearly all the dermoscopic criteria originally proposed by the IDS are applicable even to darker phototypes, several additional variables need to be assessed.

During the past two decades, anatomy instruction has changed due to curricular reforms in medical schools. Reduction in total hours of anatomy course and cadaver dissection, as well as shifts towards an integrated curricula has raised questions whether changes have had a negative impact on the students’ knowledge of anatomy. Our purpose was to investigate the effect of changes in course hours, curriculum type, and laboratory experience on USMLE Step 1 and Step 2 CK scores. Results of 2009 AAA online survey of anatomy course directors from 54 LCME‐accredited schools were matched with USMLE scores for 6,411 examinees taking Step 1 for the first time in 2009. The USMLE scores included Step 1 total test scores, Step 1 gross anatomy sub‐scores, and Step 2 CK total test scores. Analyses of data indicate that for all three USMLE scores, examinees from schools with stand‐alone gross anatomy courses slightly outperformed examinees from schools with integrated curricula. Conversely, the number of course hours had no effect on how students performed on Step 1 or Step 2 CK. Examinees that were exposed to both dissection and prosection slightly outperformed on Step 2 examinees that had dissection only. While these relationships are statistically significant, they may not be practically meaningful and more research is needed to fully explore different aspects of anatomy curricula and retention of anatomy knowledge.

3528 Background: CALGB 80405 is a phase III clinical trial of FOLFOX and FOLFIRI w/ randomly assigned cetuximab or bevacizumab. Novel machine learning approaches to the study dataset provide valuable insights into CRC prognosis and management of CRC progression. Methods: Using a Monte Carlo Bayesian Generalized Linear Model analytical platform, we built an ensemble of models for overall survival (OS). We used 99 baseline and demographic variables, including 1904 patients w/ 1o side and 949 w/ KRAS wild-type status. Building an ensemble of predictive models reduces risk of overfitting, estimates model uncertainty and identifies key variables by model consensus as measured by ensemble frequency (freq). We fit gender and 1o side (L vs R) stratum-specific models to examine differences in drivers of disease in those strata. Results: 1o side (avg Cox hazard ratio = 0.89, R side reference), ECOG performance status (1.30, reference level 0), AST concentration (1.01), peripheral neutrophil percentage (1.01) and local primary and abdominal site of disease indicators (1.22; 1.26) were key variables predictive of OS ( > 75% freq). In 1o side stratum-specific models, urine protein level (1.61), treatment intent (0.75, nonpalliative as reference) and hemoglobin concentration (0.85) were more associated w/ L side progression (freq > 85% in L stratum model, < 20% in R), while liver and lung sites of disease (2.3; 1.09) were more associated w/ R side progression (freq > 65% in R stratum model, < 20% in L). Predictors of 1o left-sidedness included age (avg log odds ratio = 0.02), hemoglobin (0.41), and abdominal (3.79) and liver (0.68) sites of disease. Modest differences in disease prognostic factors existed between genders: women more influenced by metastatic status, age, liver site of disease and creatinine level; men more influenced by urine protein level and prior diabetes. Conclusions: 1o side plays a central role in potentially explaining both variation in OS and differences in drivers of OS. Availability of these measures at baseline enables better sense of disease course at initiation of treatment. Support: U10CA180821, U10CA180882, Eli Lilly & Co., Genentech, Pfizer Clinical trial information: NCT00265850.

AbstractBackgroundThe benign and malignant patterns of acral melanocytic naevi (AMN) and acral melanomas (AM) have been defined in a series of retrospective studies. A three‐step algorithm was developed to determine when to biopsy acral melanocytic lesions. This algorithm has only been applied to a Japanese population.ObjectivesOur study aimed to review the current management strategy of acral melanocytic lesions and to investigate the utility of the three‐step algorithm in a predominately Caucasian cohort.MethodsA retrospective search of the pathology and image databases at Mayo Clinic was performed between the years 2006 and 2016. Only cases located on a volar surface with dermoscopic images were included. Two dermatologists reviewed all dermoscopic images and assigned a global dermoscopic pattern. Clinical and follow‐up data were gathered by chart review. All lesions with known diameter and pathological diagnosis were used for the three‐step algorithm.ResultsRegular fibrillar and ridge patterns were more likely to be biopsied (P = 0.01). The majority of AMN (58.1%) and AM (60%) biopsied were due to physician‐deemed concerning dermoscopic patterns. 39.2% of these cases were parallel furrow, lattice‐like or regular fibrillar. When patients were asked to follow‐up within a 3‐ to 6‐month period, only 16.7% of the patients returned within that interval. The three‐step algorithm would have correctly identified four of five AM for biopsy, missing a 6 mm, multicomponent, invasive melanoma.ConclusionWe found one major educational gap in the recognition of low‐risk lesions with high rates of biopsy of the fibrillary pattern. Recognizing low‐risk dermoscopic patterns could reduce the rate of biopsy of AMN by 23.3%. We identified two major practice gaps, poor patient compliance with follow‐up and the potential insensitivity of the three‐step algorithm to small multicomponent acral melanocytic lesions.

AbstractTrichothiodystrophy is a rare autosomal recessive disorder resulting in a broad range of systemic abnormalities. Polarizing microscopy of the hair reveals the pathognomic “tiger tail” of alternating light and dark bands, but the need for a microscope prevents rapid bedside diagnosis. We describe a new technique for the bedside diagnosis of trichothiodystrophy using a handheld polarizing dermatoscope, precluding the need for microscopic examination.

AbstractBackgroundDiagnosis of suspected basal cell carcinoma (BCC) is typically confirmed with incisional biopsy before referral to final surgery.ObjectiveTo investigate the clinical confidence and accuracy of physicians making a diagnosis of BCC based on dermoscopic and reflectance confocal microscopy (RCM) features.MethodsThis study was designed as a simulation to determine the certainty and willingness to refer to surgery without previous biopsy confirmation of BCC. Study subjects were identified with suspected BCC. Dermoscopic and RCM lesion images were obtained before biopsy. Eight clinicians with various expertise levels blindly interpreted these images and chose among four hypothetical treatment options: definite BCC, refer directly to surgery without biopsy; other malignancy, perform biopsy for diagnosis; uncertain diagnosis, perform biopsy; benign, do not biopsy. Decisions for treatment were based on dermoscopic images alone and, subsequently, on dermoscopic and RCM images combined.ResultsThe sensitivity for referral to surgery without biopsy was 67.6% with the use of dermoscopy; the positive predictive value (PPV) was 97.0%. Adding RCM increased the sensitivity to 76.5% and the PPV to 98.6%.ConclusionsDermoscopy provides a high PPV for BCC. The addition of RCM to dermoscopy increases diagnostic sensitivity, particularly in less experienced dermoscopists. Physician behavior might be different if actual referrals were made for surgery without biopsy.