Loss of the tumor suppressor CYLD enhances Wnt/beta-catenin signaling through K63-linked ubiquitination of Dvl.

The mechanism by which Wnt receptors transduce signals to activate downstream beta-catenin-mediated target gene transcription remains incompletely understood but involves Frizzled (Fz) receptor-mediated plasma membrane recruitment and activation of the cytoplasmic effector Dishevelled (Dvl). Here, we identify the deubiquitinating enzyme CYLD, the familial cylindromatosis tumor suppressor gene, as a negative regulator of proximal events in Wnt/beta-catenin signaling. Depletion of CYLD from cultured cells markedly enhances Wnt-induced accumulation of beta-catenin and target gene activation. Moreover, we demonstrate hyperactive Wnt signaling in human cylindroma skin tumors that arise from mutations in CYLD. At the molecular level, CYLD interacts with and regulates K63-linked ubiquitination of Dvl. Enhanced ubiquitination of the polymerization-prone DIX domain in CYLD-deficient cells positively links to the signaling activity of Dvl. Together, our results argue that loss of CYLD instigates tumor growth in human cylindromatosis through a mechanism in which hyperubiquitination of polymerized Dvl drives enhancement of Wnt responses.

Sneddon syndrome and the diagnostic value of skin biopsies - three young patients with intracerebral lesions and livedo racemosa.

Sneddon syndrome is a rare disorder characterised by generalised livedo racemosa of the skin with extracutaneous neurological symptoms like headache, vertigo, transient ischaemic attacks (TIA), stroke, and seizures. Diagnosis of Sneddon syndrome is based on these clinical features and positive findings in skin biopsies, namely the histological proof of occlusion of arterioles by intimal proliferation. We describe three cases of young patients with clinical characteristics of Sneddon syndrome, but in only two cases could this diagnosis be confirmed by skin biopsies. These cases stress the difficulty of diagnosing Sneddon syndrome and show the additive value of skin biopsies in this process.

Subcutaneous panniculitis-like T-cell lymphoma: definition, classification, and prognostic factors: an EORTC Cutaneous Lymphoma Group Study of 83 cases.

In the WHO classification, subcutaneous panniculitis-like T-cell lymphoma (SPTL) is defined as a distinct type of T-cell lymphoma with an aggressive clinical behavior. Recent studies suggest that distinction should be made between SPTL with an alpha/beta T-cell phenotype (SPTL-AB) and SPTL with a gammadelta T-cell phenotype (SPTL-GD), but studies are limited. To better define their clinicopathologic features, immunophenotype, treatment, and survival, 63 SPTL-ABs and 20 SPTL-GDs were studied at a workshop of the EORTC Cutaneous Lymphoma Group. SPTL-ABs were generally confined to the subcutis, had a CD4-, CD8+, CD56-, betaF1+ phenotype, were uncommonly associated with a hemophagocytic syndrome (HPS; 17%), and had a favorable prognosis (5-year overall survival [OS]: 82%). SPTL-AB patients without HPS had a significantly better survival than patients with HPS (5-year OS: 91% vs 46%; P<.001). SPTL-GDs often showed (epi)dermal involvement and/or ulceration, a CD4-, CD8-, CD56+/-, betaF1- T-cell phenotype, and poor prognosis (5-year OS: 11%), irrespective of the presence of HPS or type of treatment. These results indicate that SPTL-AB and SPTL-GD are distinct entities, and justify that the term SPTL should further be used only for SPTL-AB. SPTL-ABs without associated HPS have an excellent prognosis, and multiagent chemotherapy as first choice of treatment should be questioned.

Diagnosis of ocular toxocariasis by establishing intraocular antibody production.

PURPOSE: To investigate the role of Toxocara canis in posterior uveitis of undetermined origin. DESIGN: Retrospective case-study. METHODS: Paired ocular fluid (47 aqueous humor [AH] and two vitreous fluids) and serum samples of 37 adults and 12 children with undetermined posterior uveitis were retrospectively analyzed for intraocular IgG antibody production against Toxocara canis by enzyme-linked immunosorbent assay and Goldmann-Witmer coefficient (GWC) determination. Previous diagnostic investigation by polymerase chain reaction and GWC for Herpes simplex virus, Varicella zoster virus, and Toxoplasma gondii had not provided a cause of the posterior uveitis. RESULTS: Three of 12 (25%) children showed intraocular IgG production against Toxocara canis. One child had vitritis, one presented with a low-grade uveitis and a peripheral retinal lesion, and the third had posterior uveitis and a chorioretinal scar. All three children had AH IgG titers exceeding those of the corresponding serum. In fact, two children had low Toxocara serum IgG titers (<1:32) and would have been considered seronegative upon routine serology screening. Intraocular antibody production against Toxocara canis was absent in all 37 adults, including five seropositive patients. CONCLUSIONS: Our results indicate that ocular toxocariasis is mainly a pediatric disease. Serological screening is not informative for the diagnosis of intraocular Toxocara infection. Toxocara GWC analysis, however, can be of value when diagnosing patients with posterior focal lesions or vitritis of unknown etiology.

Is the distinction between superficial pressure ulcers and moisture lesions justifiable? A clinical-pathologic study.

OBJECTIVE: Pressure ulcers are classified into 4 distinct stages, which allows comparisons between institutions and even countries. Recently, attempts have been made to single out so-called moisture lesions from the early stages of pressure ulcer lesions as a distinct entity. METHODS: To investigate the justification for this development, 14 histopathologic samples from patients with both incontinence and pressure ulcer lesions were studied in an attempt to delineate differences in the pathophysiology and histopathology. RESULTS: Two distinct histopathologic pictures emerged: an ischemic pattern and a pattern of irritation. The latter appeared to be associated with lesions that clinically fit the description of moisture lesions, but this association was not absolute. CONCLUSIONS: There is no justification for singling out moisture lesions from pressure ulcer lesions. The distinction may even be dangerous when proper preventive measures for the development of pressure ulcers are not taken because of the existence of a possible moisture lesion.

Reclassification of 300 primary cutaneous B-Cell lymphomas according to the new WHO-EORTC classification for cutaneous lymphomas: comparison with previous classifications and identification of prognostic markers.

PURPOSE: In the new WHO-European Organisation for Research and Treatment of Cancer (WHO-EORTC) classification for cutaneous lymphomas three major groups of primary cutaneous B-cell lymphoma (CBCL) are distinguished: primary cutaneous marginal zone B-cell lymphoma (PCMZL) and primary cutaneous follicle center lymphoma (PCFCL) with a good prognosis, and primary cutaneous large B-cell lymphoma, leg type (PCLBCL-LT), with an intermediate-level prognosis. This study aimed to assess the clinical significance of the new classification compared with previous classification schemes (EORTC 1997; WHO 2001) and to define prognostic factors within the newly defined categories. PATIENTS AND METHODS: In the present study clinical data and histologic sections of 300 patients with CBCL, formerly classified according to the EORTC classification, were reviewed and reclassified according to the WHO and the new WHO-EORTC classification schemes. RESULTS: After reclassification, the study comprised 71 patients with PCMZL, 171 patients with PCFCL, and 58 patients with PCLBCL-LT, showing 5-year disease-specific survivals of 98%, 95%, and 50%, respectively. When compared with the EORTC and WHO schemes, 5.3% and 36.3% of patients with CBCL were reclassified into another prognostic category. Multivariate analysis of PCFCL revealed localization on the leg and expression of FOXP1 as independent parameters associated with a poor prognosis. Expression of Bcl-2 or MUM-1 had no significant effect on survival in this group. In PCLBCL-LT, no independent prognostic parameters were found. CONCLUSION: These results emphasize the clinical significance of the WHO-EORTC classification, but suggest that within the group of PCFCL, distinction should be made between lymphomas presenting on the legs and lymphomas presenting at other sites.

Acromegaly in a multiple endocrine neoplasia type 1 (MEN1) family with low penetrance of the disease.

Multiple endocrine neoplasia type 1 (MEN1) is an inherited syndrome that is characterised by the occurrence of tumours in the parathyroid glands, the endocrine pancreas, the pituitary gland and the adrenal glands and by neuroendocrine carcinoid tumours, often at a young age. The penetrance of MEN1 among gene carriers is reported to be high; 82-99% at age 50. We present a patient with a history of parathyroid adenomas also showing signs of acromegaly. He turned out to be a carrier of a MEN1 germ-line mutation in intron 3 (IVS3-6C > G). This germ-line mutation was also found in nine of his family members. However, none of these relatives have developed any MEN1-related lesion yet, although several are older than 60 years. To our knowledge, a MEN1 family with as few clinical features as this family has not been reported to date. Because MEN1 patients have an increased risk of developing acromegaly, insulin-like growth factor (IGF-I) levels are monitored periodically. We investigated whether IGF-I levels might serve as a presymptomatic marker for acromegaly; 9% (3/33) of MEN1 patients showed temporary IGF-I elevations. One patient (1/3) later developed clinical signs of acromegaly. Possibly, acromegaly in MEN1 is preceded by a transient preacromegalic state.

Extra-domain-A fibronectin: a new marker of fibrosis in cutaneous graft-versus-host disease.

One of the major complications that limit the success of allogeneic stem cell transplantation is graft-versus-host disease (GVHD). The major target organ in GVHD is the skin. Cutaneous GVHD can eventually lead to fibrosis of the skin. Fibronectin mediates a variety of cellular interactions with the extracellular matrix. The molecular and functional diversity of fibronectin (FN) arises from alternative splicing of pre-mRNA. In normal circumstances endothelial cells and fibroblasts synthesize FN without the ED-A domain. In tissue repair and pathologic circumstances such as fibrosis, the ED-A domain is expressed. We hypothesize that expression of ED-A FN is upregulated in patients with cutaneous GVHD. In frozen skin biopsies the expression of ED-A FN was measured at the protein level by immunohistochemistry and at the mRNA level by quantitative real-time PCR (qPCR). In normal control skin, immunohistochemistry showed slight deposits of ED-A FN just under the basal layer. The expression of ED-A FN significantly increased in acute cutaneous GVHD (p<0.05) and ED-A FN was strongly deposited in chronic cutaneous GVHD (p<0.001). Quantitative PCR also showed increased expression of ED-A FN mRNA in acute and chronic cutaneous GVHD compared with normal control skin (p=0.07 and 0.039, respectively). The expression of ED-A FN is increased in the skin of patients with cutaneous GVHD measured both with immunohistochemistry and qPCR. ED-A FN is a new marker of fibrosis in the skin of patients with cutaneous GVHD.

The glucagonoma syndrome and necrolytic migratory erythema: a clinical review.

The glucagonoma syndrome is a rare disease in which a typical skin disorder, necrolytic migratory erythema, is often one of the first presenting symptoms. Weight loss and diabetes mellitus are two other prevalent characteristics of this syndrome. Necrolytic migratory erythema belongs to the recently recognized family of deficiency dermatoses of which zinc deficiency, necrolytic acral erythema and pellagra are also members. It is typically characterized on skin biopsies by necrolysis of the upper epidermis with vacuolated keratinocytes. In persistent hyperglucagonemia, excessive stimulation of basic metabolic pathways results in diabetes mellitus at the expense of tissue glycogen stores, and muscle and fat mass. Multiple (essential) nutrient and vitamin B deficiencies develop, which contribute to the dermatosis. In addition, glucagonomas may produce various other products, like pancreatic polypeptide, that add to the catabolic effects of glucagon.

Anti-CD20 monoclonal antibody treatment in 6 patients with therapy-refractory chronic graft-versus-host disease.

Chronic graft-versus-host disease (cGVHD) is an important determinant of long-term morbidity and mortality in allogeneic stem cell transplantation patients. Because cGVHD has clinical, histologic, and laboratory findings of autoimmune diseases and anti-B-cell therapy has shown efficacy in autoimmune diseases, we hypothesized that monoclonal anti-CD20 antibody therapy might improve patients with cGVHD. We treated 5 men and 1 woman with therapy-refractory extensive cGVHD with anti-CD20 monoclonal antibody. Intravenous infusion was given at a weekly dose of 375 mg/m(2) for 4 weeks. In case of incomplete clinical response, additional courses of 4 weeks were given. Five patients responded to treatment with marked clinical, biochemical, and histologic improvement. One patient failed to respond. Anti-CD20 monoclonal antibody seems to be effective in cGVHD. A controlled trial is mandatory to confirm these results. The outcome of this study suggests a participating role of B cells in the pathogenesis of cGVHD.

A new xenograft model for graft-versus-host disease by intravenous transfer of human peripheral blood mononuclear cells in RAG2-/- gammac-/- double-mutant mice.

The safe application of new strategies for the treatment of graft-versus-host disease (GVHD) is hampered by the lack of a clinically relevant model for preclinical testing. Current models are based on intraperitoneal transfer of human peripheral blood mononuclear cells (huPBMCs) into NOD-SCID (nonobese diabetic-severe combined immunodeficient)/SCID mice. Intravenous transfer would be preferred but this has always been ineffective. We developed a new model for xenogeneic GVHD (X-GVHD) by intravenous transfer of huPBMCs into RAG2-/- gammac-/-mice. Our results show a high human T-cell chimerism of more than 20% (up to 98%) in more than 90% of mice, associated with a consistent development of XGVHD within 14 to 28 days and a total mortality rate of 85% shorter than 2 months. After murine macrophage depletion, engraftment was earlier and equally high with lower doses of huPBMCs. Human macrophages were also absent in these mice. Purified huCD3+ cells showed a similar X-GVH effect with contribution of both CD4 and CD8 phenotypes. Human immunoglobulins and cytokines were produced in diseased mice. One of 30 mice developed chronic X-GVHD with skin histology similar to human GVHD. In conclusion, we present a new model for X-GVHD by intravenous transfer of huPBMCs in RAG2-/- gammac-/- mice. Murine and human macrophages do not seem to be necessary for acute X-GVHD in this model.

Peripheral T-cell lymphomas unspecified presenting in the skin: analysis of prognostic factors in a group of 82 patients.

In the present study the clinicopathologic and immunophenotypic features of 82 patients with a CD30- peripheral T-cell lymphoma, unspecified, presenting in the skin were evaluated. The purpose of this study was to find out whether subdivision of these lymphomas on the basis of cell size, phenotype, or presentation with only skin lesions is clinically relevant. The study group included 46 primary cutaneous CD30- large cell lymphomas and 17 small/medium-sized T-cell lymphomas as well as 17 peripheral T-cell lymphomas with both skin and extracutaneous disease at the time of diagnosis. Patients with primary cutaneous small- or medium-sized T-cell lymphomas had a significantly better prognosis (5-year-overall survival, 45%) than patients with primary cutaneous CD30- large T-cell lymphomas (12%) and patients presenting with concurrent extracutaneous disease (12%). The favorable prognosis in this group with primary cutaneous small- or medium-sized T-cell lymphomas was particularly found in patients presenting with localized skin lesions expressing a CD3+CD4+CD8- phenotype. In the primary cutaneous T-cell lymphoma (CTCL) group and in the concurrent group, neither extent of skin lesions nor phenotype had any effect on survival. Our results indicate that peripheral T-cell lymphomas, unspecified, presenting in the skin have an unfavorable prognosis, irrespective of the presence or absence of extracutaneous disease at the time of diagnosis, cell size, and expression of a CD4+ or CD8+ phenotype. The only exception was a group of primary cutaneous small- or medium-sized pleomorphic CTCLs with a CD3+CD4+CD8- phenotype and presenting with localized skin lesions.

Sequential ACTH and catecholamine secretion in a phaeochromocytoma.

OBJECTIVE: We describe a patient with an ACTH-producing phaeochromocytoma who initially presented with hypercortisolism and normal catecholamine concentrations, followed by near-normalisation of ACTH secretion and massive catecholamine secretion. In vitro studies were carried out on the tumour to evaluate the interaction between the tumour cells and normal adrenal cortex. METHODS AND RESULTS: A 30-year-old man initially presented with severe hypercortisolism, biochemical evidence of ectopic ACTH production, a tumour in the right adrenal gland without a hyperintense signal on the T2-weighted images at magnetic resonance imaging (MRI) scanning, and normal urinary metanephrine concentrations. After 6 months, ACTH production had almost completely resolved, but the patient developed severe hypertension and excess catecholamines. At repeated MRI-scanning, the T2-weighted images showed a hyperintense signal, in agreement with the diagnosis of phaeochromocytoma. Although the initial T1-weighted images suggested bleeding in the adrenal tumour, no signs of bleeding were observed after surgical removal. The diagnosis of ACTH-producing phaeochromocytoma was histologically and immunohistochemically confirmed. Cultured cell suspensions of the tumour secreted ACTH, which stimulated cortisol production in the ipsilateral adrenocortical cells. CONCLUSION: This case demonstrates that the biological activity of an ACTH-producing phaeochromocytoma can vary significantly in time, which may be the consequence of different stages of tumour differentiation.