Ziad Khamaysi

Mutations in GALNT3 , encoding a protein involved in O-linked glycosylation, cause familial tumoral calcinosis

Familial tumoral calcinosis (FTC; OMIM 211900) is a severe autosomal recessive metabolic disorder that manifests with hyperphosphatemia and massive calcium deposits in the skin and subcutaneous tissues. Using linkage analysis, we mapped the gene underlying FTC to 2q24–q31. This region includes the gene GALNT3, which encodes a glycosyltransferase responsible for initiating mucin-type O-glycosylation. Sequence analysis of GALNT3 identified biallelic deleterious mutations in all individuals with FTC, suggesting that defective post-translational modification underlies the disease.

Positive patch test reactions to allergens of the dental series and the relation to the clinical presentations.

The clinical manifestations of contact allergic dermatitis to dental materials are not uniform. This study was performed to detect the frequent allergens in the dental series associated with contact dermatitis and to define the causal relationship between the different allergens and the relevant clinical presentations. Between the years 2000 and 2004, 134 patients, aged 20–80 years, were patch tested. 121 patients were included in the study. The most frequent oral manifestations were cheilitis and perioral dermatitis (25.6%), burning mouth (15.7%), lichenoid reaction (14.0%), and orofacial granulomatosis (10.7%). 18 (14.9%) patients were dental personnel, all of whom suffered from hand dermatitis. The common allergens detected included goldsodiumthiosulphate (14.0%), nickel sulfate (13.2%), mercury (9.9%), palladium chloride (7.4%), cobalt chloride (5.0%), and 2‐hydroxyethyl methacrylate (5.8%). Positive reactions to metals were frequent in all the different clinical variants, and no specific association between a specific clinical presentation and a particular allergen was found. Allergy to mercury was not a significant factor contributing to the pathogenesis of oral lichenoid reactions. However, a strong association with contact allergy to mercury in dental fillings was found in 2 patients with orofacial granulomatosis.

Galli–Galli disease is an acantholytic variant of Dowling–Degos disease

Dowling–Degos disease (DDD; MIM 179850) is a rare autosomal dominant disorder characterized by reticulate flexural hyperpigmentation associated with hyperkeratotic papules, pitted perioral scars and comedo-like lesions or cysts. Characteristic histopathological features include filiform epithelial downgrowths of the rete ridges, typically involving the follicular infundibulum, basilar hyperpigmentation and dermal melanosis. Follicular retention cysts and perivascular mononuclear infiltrates can also be present. Galli–Galli disease is a term that has been used to describe patients displaying prominent acantholytic changes on histology, in addition to clinical and pathological features resembling those of DDD. Two mutations in KRT5, encoding one of the two major basal epidermal keratin intermediate filaments, were recently reported to underlie DDD in a number of European cases. In the present study, we report a novel mutation in KRT5 in a patient with clinical and histopathological features typical of Galli–Galli disease.

Insect bite-like reaction associated with mantle cell lymphoma: clinicopathological, immunopathological, and molecular studies.

A cutaneous eruption simulating insect bites has been repeatedly described in association with chronic lymphocytic leukemia (CLL). It was only rarely described with mantle cell lymphoma (MCL). Our study was performed to elucidate the clinical, histologic, immunopathological, and molecular characteristics of insect bite like reaction (IBLR) associated with MCL. The clinical presentation and histologic findings in 3 IBLR cases associated with MCL were found to be similar to 3 IBLR cases associated with CLL. The eruptions consisted of itchy erythematous papules, nodules, plaques, and vesicles. Non-vesicular lesions were characterized histologically by normal or mildly spongiotic epidermis. Vesicular lesions were characterized by marked spongiosis and intraepidermal spongiotic vesicles containing eosinophils, or marked subepidermal edema occasionally leading to a dermoepidermal separation. Most of the lesions were characterized by superficial and mid dermal to deep perivascular and interstitial, and occasionally periadnexal, inflammatory-cell infiltrate consisting of mononuclear cells and eosinophils. The densities of the infiltrates varied and the inflammatory-cell infiltrate extended often into the fat lobules. Neutrophils and nuclear dust were found more frequently and abundantly in the IBLR lesions associated with MCL. Immunophenotyping, direct immunofluorescence (DIF) tests, and IgH gene rearrangement studies were performed in the lesions associated with MCL only. The majority of the infiltrating lymphocytes were CD3+, CD5+ and CD43+, more CD4+ than CD8+, and only a small minority was CD20+. The cells did not stain for bcl-1 protein and CD30, and with no evidence of clonality. The DIF test result was negative. The IBLR eruption associated with MCL resembles clinically and histologically IBLR associated with CLL. The eruption seems to be reactive rather than neoplastic, because there is no evidence of MCL involvement in the skin lesions.

The applicability of the new WHO-EORTC classification of primary cutaneous lymphomas to a single referral center.

Recent years have witnessed differences between the World Health Organization (WHO) and the European Organization for Research and Treatment of Cancer (EORTC) classification systems of primary cutaneous lymphomas (PCLs). Recently, a joint WHO-EORTC classification system for PCLs has been reached. This study was performed to assess the applicability of this new classification to a single referral center. All new PCL cases, excluding mycosis fungoides and Sezary syndrome, who were referred from 1999 to 2005 were included. The histological, immunohistochemical stainings and molecular studies were reviewed, and additional stains were performed as needed. The cases were then reclassified according to the WHO-EORTC classifications. The clinical files were also studied, and the patients were followed up clinically. There were 43 new non-mycosis fungoides/Sezary syndrome PCLs, including 29 B-cell lymphomas of which 14 were follicle center lymphoma, 10 marginal zone lymphoma, 4 diffuse large-B-cell lymphoma, leg type, and 1 diffuse large-B-cell lymphoma, other. The 14 T-cell lymphomas included 5 cases of lymphomatoid papulosis, 2 CD30+ anaplastic large-cell lymphomas, 1 NK/T-cell lymphoma, and 6 peripheral T-cell lymphomas, unspecified. Of the 6 “unspecified” T-cell lymphomas, 3 were CD4+ small/medium-sized pleomorphic T-cell lymphoma, which is considered currently a provisional entity under the unspecified T-cell category. The remaining 3 cases could not be classified beyond the unspecified T-cell category, of which 2 cases had an aggressive course. The new WHO-EORTC classification is applicable to most non-mycosis fungoides/Sezary syndrome PCL cases, especially the B-cell lymphomas. However, there is still a substantial subset of T-cell PCLs which cannot be classified beyond the unspecified peripheral T-cell category, some of which may have an aggressive course.

A unique pattern of dyskeratosis characterizes epidermolytic hyperkeratosis and epidermolytic palmoplantar keratoderma.

Hereditary skin diseases that are characterized ultrastructurally by intracellular clumpings of keratin tonofilaments, such as Darier disease and Ichthyosis Hystrix of Curth-Macklin, display epidermal dyskeratosis also histologically. Epidermolytic hyperkeratosis (EHK) and epidermolytic palmoplantar keratoderma (Voerner type) (EPPK) are 2 types of autosomal dominant keratodermas, which are also characterized ultrastructurally by intracellular clumpings of tonofilaments but usually without a clear description of histological dyskeratosis. The main aim of the present study was to characterize the histologic signs of keratin aggregation and clumping in the involved epidermis of EHK and EPPK. Two cases of EHK caused by KRT1 mutations and 4 cases of EPPK caused by KRT9 mutations were studied. The biopsies were obtained mostly from the involved skin of the palm. All 6 biopsies were studied histologically, and 4 biopsies (2 EHKs and 2 EPPKs) were also studied ultrastructurally. All 6 cases displayed the characteristic histological epidermolytic changes. In addition, intracytoplasmic and perinuclear eosinophilic homogenizations and round to oval eosinophilic inclusions were identified with varying frequencies in the involved epidermis of all 6 cases. These findings, which were more prominent in the EHK cases, corresponded most likely to the intracytoplasmic aggregates of tonofilaments and to the large round to oval dense clumps of tonofilaments, which were observed ultrastructurally. In conclusion, varying degrees of dyskeratosis are frequently present in EHK and EPPK and should be considered to be a histological characteristic of these disorders.

Contact hypersensitivity in patients with primary cutaneous lymphoproliferative disorders

Background  One of the suggested causes of primary cutaneous lymphoproliferative disorders is persistent antigenic stimulation.

Multifocal Congenital Lymphangioendotheliomatosis Without Gastrointestinal Bleeding and/or Thrombocytopenia

A 5-month-old male infant presented with an increasing number of widespread asymptomatic violaceous cutaneous macules, papules, and nodules since birth. He is 1 of the 2 identical twins born to unrelated healthy parents. Histology revealed proliferation of dilated thin-walled vascular channels lined by bland endothelial cells in the dermis and subcutis. In some of the vascular channels, there were formations of intravascular papillae surrounded by hobnail endothelial cells. Immunohistochemistry demonstrated positive staining for CD31, CD34 factor VIII and vascular endothelial growth factor-3 (VEGFR-3) and negative staining for D2-40 and latencyassociated nuclear antigen-1 (LANA-1). The clinical and histologic findings were compatible with multifocal congenital lymphangioendothelionmatosis with thrombocytopenia, except that a year of follow-up was uneventful and no gastrointestinal bleeding or thrombocytopenia was recorded.

Acne during adolescence did not predict skin rash reaction to cetuximab.

Cetuximab, a monoclonal antibody, is a part of the treatment for metastatic colorectal cancer. The most common side effect of cetuximab is skin rash, which has a similar distribution to acne vulgaris and some overlapping pathophysiological mechanisms. The aim of the current study was to determine whether acne vulgaris in adolescence (AinA) is predictive of a cetuximab-related rash to better understand the pathogenesis of this side effect and explore potential preventive actions. From July 2013 to June 2015, patients with metastatic colorectal cancer planned for treatment with cetuximab were enrolled in the study. Before initiating treatment, patients completed a questionnaire evaluating endocrine disorders, other chronic diseases, smoking, chronic medications, allergies, and dermatologic history of AinA and its severity. Patients were followed for 6 months. Data were collected from 32 participants (16 women, 16 men). Twenty-three (69%) patients experienced a cetuximab-associated skin reaction. Nine (28%) patients had a history of AinA. Of these, seven developed a cetuximab-associated skin reaction. Three of the five (60%) patients who used proton pump inhibitors (PPIs) developed severe (grades 3–4) skin toxicity versus 4/27 (15%) patients who were not on PPIs (P=0.057). The degree of skin toxicity correlated to the median time-to-tumor-progression: 2 months for patients with grades 0–1 compared with 5.5 months for grades 2–4 skin toxicity (P=0.047, 95% confidence interval 1.06–4.95). No significant correlation was found between AinA and cetuximab-associated skin reactions. The correlation between PPI treatment and severe skin toxicity related to cetuximab should be examined further.