Markel Cell Carcinoma

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine tumour of the skin with high rate of local recurrence and distant metastatic potential leading to poor outcomes. Merkel cells are normally found as innervated clusters of cells around hair follicles in the basal layer of the epidermis and are thought to function as touch receptors. Here, we describe a case of MCC in a 71-year-old female and provide an up-to-date review of the literature pertinent to the management of MCC. KEYWORDS: merkell cell carcinoma, diagnosis, imunohistochemistry, management

Brown Bowel Syndrome: A Multi-institutional Case Series

Copyright © 2020 Wolters Kluwer Health, Inc. Unauthorized reproduction of the article is prohibited. Brown bowel syndrome (BBS) is a rare condition associated with vitamin E deficiency and defined by prominent lipofuscin deposition in the muscularis propria. Eight unique cases of BBS were identified: 5 men and 3 women (mean age=58.6 y). Pertinent comorbidities included bariatric surgery=2, malnourishment=2, Crohn=2, cystic fibrosis=1, alcohol and cocaine abuse=1, and prior small bowel resections=1. Presenting symptoms included abdominal pain=3, bleeding=1, nausea and vomiting=1, and nonresponsiveness=1. Imaging studies were often abnormal: thickened bowel wall=3 (1 with a mass), small bowel obstruction=2, and edematous and dilated bowel wall=2. Most specimens were surgical resections (n=7, autopsy=1): extended right colectomy=2, small bowel only=5 (terminal ileum=3, jejunum=2). Two specimens were grossly described as mahogany, and 1 case contained a perforation. Histologic sections of all cases showed finely granular, brown cytoplasmic piNorthwell Healthnt in smooth muscle cells on hematoxylin and eosin. This piNorthwell Healthnt was most conspicuous in the muscularis propria (small bowel\u3ecolon), and it was not identified in the mucosa. The piNorthwell Healthnt was reactive with Fontana-Masson, carbol lipofuscin, Periodic acid-Schiff, and Periodic acid-Schiff with diastase, and electron microscopy was compatible with lipofuscin. The mean clinical follow-up was 208 weeks: 1 patient died of complications of encephalitis, the others were alive and well. BBS is important to recognize because it is linked with malnutrition, specifically vitamin E deficiency, and it can (rarely) clinically simulate malignancy. The diagnosis is based on the identification of the lipofuscin piNorthwell Healthnt in the cytoplasm of smooth muscle cells, which is most easily seen in the muscularis propria of the small bowel

Low Referral Rate for Genetic Testing in Racially and Ethnically Diverse Patients Despite Universal Colorectal Cancer Screening

Guidelines recommend that all colorectal tumors be assessed for mismatch repair deficiency, which could increase identification of patients with Lynch syndrome. This is of particular importance for minority populations, in whom hereditary syndromes are under diagnosed. We compared rates and outcomes of testing all tumor samples (universal testing) collected from a racially and ethnically diverse population for features of Lynch syndrome. We performed a retrospective analysis of colorectal tumors tested from 2012 through 2016 at 4 academic centers. Tumor samples were collected from 767 patients with colorectal cancer (52% non-Hispanic white [NHW], 26% African American, and 17% Hispanic patients). We assessed rates of tumor testing, recommendations for genetic evaluation, rates of attending a genetic evaluation, and performance of germline testing overall and by race/ethnicity. We performed univariate and multivariate regression analyses. Overall, 92% of colorectal tumors were analyzed for mismatch repair deficiency without significant differences among races/ethnicities. However, minority patients were significantly less likely to be referred for genetic evaluation (21.2% for NHW patients vs 16.9% for African American patients and 10.9% for Hispanic patients; P = .02). Rates of genetic testing were also lower among minority patients (10.7% for NHW patients vs 6.0% for AA patients and 3.1% for Hispanic patients; P < .01). On multivariate analysis, African American race, older age, and medical center were independently associated with lack of referral for genetic evaluation and genetic testing. In a retrospective analysis, we found that despite similar rates of colorectal tumor analysis, minority patients are less likely to be recommended for genetic evaluation or to undergo germline testing for Lynch syndrome. Improvements in institutional practices in follow up after tumor testing could reduce barriers to diagnosis of Lynch diagnosis in minorities

Evaporation Rates and Bénard-Marangoni Supercriticality Levels for Liquid Layers Under an Inert Gas Flow

In this work, we propose an approximate model of evaporation-induced Bénard-Marangoni instabilities in a volatile liquid layer with a free surface along which an inert gas flow is externally imposed. This setting corresponds to the configuration foreseen for the ESA-"EVAPORATION PATTERNS" space experiment, which involves HFE-7100 and nitrogen as working fluids. The approximate model consists in replacing the actual flowing gas layer by an "equivalent" gas at rest, with a thickness that is determined in order to yield comparable global evaporation rates. This allows studying the actual system in terms of an equivalent Pearson's problem (with a suitably defined wavenumber-dependent Biot number at the free surface), allowing to estimate how far above critical the system is for given control parameters. Among these, a parametric analysis is carried out as a function of the liquid-layer thickness, the flow rate of the gas, its relative humidity at the inlet, and the ambient pressure and temperature. © 2013 Springer Science+Business Media Dordrecht.SCOPUS: ar.jinfo:eu-repo/semantics/publishe