Merkel Cell Carcinoma of the Upper Eye Lid with Atypical Clinical Appearance. / Merkel-Zell-Karzinome des Oberlides mit ungewöhnlichem klinischem Erscheinungsbild.

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine skin tumor that occurs mainly in the sun-exposed head and neck region, but rarely in the eyelid region. Early lymphogenic spread often leads to locoregional metastases, which is why early diagnosis is crucial. Classically, periocular MCC presents as a reddish-livid nodule in elderly patients, a visual diagnosis. However, given its low incidence and variable appearance, diagnosis can also be challenging. In both cases presented here, the MCC presented as a skin-colored swelling. In patient 1, the tumor showed a partially deep subaponeurotic localization and mimicked a B-cell lymphoma histopathologically, whereas in patient 2 it imitated a diffuse chalazion clinically. After immunohistochemical characterization and exclusion of metastases, the initial clinically benign appearing lesions in both patients were classified as CK20 negative MCC. The extensive upper eyelid defects were reconstructed by Cutler-Beard plastic surgery, a particular challenge in patient 1 given the oculus unicus situation. Our two cases demonstrate that Merkel cell carcinomas not only manifest as deep red cherry-shaped tumors, but can be skin-colored and mimic benign changes when atypical in location or infiltration pattern.

A Decellularized Human Limbal Scaffold for Limbal Stem Cell Niche Reconstruction.

The transplantation of ex vivo expanded limbal epithelial progenitor cells (LEPCs) on amniotic membrane or fibrin gel is an established therapeutic strategy to regenerate the damaged corneal surface in patients with limbal stem cell deficiency (LSCD), but the long-term success rate is restricted. A scaffold with niche-specific structure and extracellular matrix (ECM) composition might have the advantage to improve long-term clinical outcomes, in particular for patients with severe damage or complete loss of the limbal niche tissue structure. Therefore, we evaluated the decellularized human limbus (DHL) as a biomimetic scaffold for the transplantation of LEPCs. Corneoscleral tissue was decellularized by sodium deoxycholate and deoxyribonuclease I in the presence or absence of dextran. We evaluated the efficiency of decellularization and its effects on the ultrastructure and ECM composition of the human corneal limbus. The recellularization of these scaffolds was studied by plating cultured LEPCs and limbal melanocytes (LMs) or by allowing cells to migrate from the host tissue following a lamellar transplantation ex vivo. Our decellularization protocol rapidly and effectively removed cellular and nuclear material while preserving the native ECM composition. In vitro recellularization by LEPCs and LMs demonstrated the good biocompatibility of the DHL and intrastromal invasion of LEPCs. Ex vivo transplantation of DHL revealed complete epithelialization as well as melanocytic and stromal repopulation from the host tissue. Thus, the generated DHL scaffold could be a promising biological material as a carrier for the transplantation of LEPCs to treat LSCD.

Preserved white matter microstructure in young patients with anorexia nervosa?

A massive but reversible reduction of cortical thickness and subcortical gray matter (GM) volumes in Anorexia Nervosa (AN) has been recently reported. However, the literature on alterations in white matter (WM) volume and microstructure changes in both acutely underweight AN (acAN) and after recovery (recAN) is sparse and results are inconclusive. Here, T1-weighted and diffusion-weighted MRI data in a sizable sample of young and medication-free acAN (n = 35), recAN (n = 32), and age-matched female healthy controls (HC, n = 62) were obtained. For analysis, a well-validated global probabilistic tractography reconstruction algorithm including rigorous motion correction implemented in FreeSurfer: TRACULA (TRActs Constrained by UnderLying Anatomy) were used. Additionally, a clustering algorithm and a multivariate pattern classification technique to WM metrics to predict group membership were applied. No group differences in either WM volume or WM microstructure were detected with standard analysis procedures either in acAN or recAN relative to HC after controlling for the number of performed statistical tests. These findings were not affected by age, IQ, or psychiatric symptoms. While cluster analysis was unsuccessful at discriminating between groups, multivariate pattern classification showed some ability to separate acAN from HC (but not recAN from HC). However, these results were not compatible with a straightforward hypothesis of impaired WM microstructure. The current findings suggest that WM integrity is largely preserved in non-chronic AN. This finding stands in contrast to findings in GM, but may help to explain the relatively intact cognitive performance of young patients with AN and provide the basis for the fast recovery of GM structures. Hum Brain Mapp 37:4069-4083, 2016. © 2016 Wiley Periodicals, Inc.

Global cortical thinning in acute anorexia nervosa normalizes following long-term weight restoration.

BACKGROUND: Anorexia nervosa (AN) is a serious eating disorder characterized by self-starvation, extreme weight loss, and alterations in brain structure. Structural magnetic resonance imaging studies have documented brain volume reductions in acute AN, but it is unclear whether they are 1) regionally specific, or 2) reversible following weight restoration. Here, we measured cortical thickness (CT) for the first time in AN. METHODS: Structural magnetic resonance imaging data were acquired from adolescent and young adult female patients with acute AN (n = 40), recovered patients following long-term weight restoration (n = 34), and an equal number of age-matched healthy control subjects. Group differences in CT were tested with well-validated procedures implemented in FreeSurfer. The mediating role of clinical variables including body mass index and drive for thinness were explored. For completeness, we also used FreeSurfer's subcortical segmentation stream to test group differences in volumes of select gray matter regions of interest. RESULTS: Vertex-wise analyses revealed significant thinning of over 85% of the cortical surface in patients with acute AN and CT normalization in recovered patients following long-term weight restoration, although normal age-related trajectories were absent in the disorder. This pattern of results was largely mirrored in subcortical volumes. We also observed a strong negative correlation between CT and drive for thinness in extrastriate regions involved in body perception. CONCLUSIONS: Structural brain anomalies in AN as expressed in CT and subcortical volume are primarily the consequence of malnutrition and unlikely to reflect premorbid trait markers or permanent scars, but longitudinal data are needed.