The sensory shark: high-quality morphological, genomic and transcriptomic data for the small-spotted catshark Scyliorhinus canicula reveal the molecular bases of sensory organ evolution in jawed vertebrates.

Cartilaginous fishes (chimaeras and elasmobranchs -sharks, skates and rays) hold a key phylogenetic position to explore the origin and diversifications of jawed vertebrates. Here, we report and integrate reference genomic, transcriptomic and morphological data in the small-spotted catshark Scyliorhinus canicula to shed light on the evolution of sensory organs. We first characterise general aspects of the catshark genome, confirming the high conservation of genome organisation across cartilaginous fishes, and investigate population genomic signatures. Taking advantage of a dense sampling of transcriptomic data, we also identify gene signatures for all major organs, including chondrichthyan specializations, and evaluate expression diversifications between paralogs within major gene families involved in sensory functions. Finally, we combine these data with 3D synchrotron imaging and in situ gene expression analyses to explore chondrichthyan-specific traits and more general evolutionary trends of sensory systems. This approach brings to light, among others, novel markers of the ampullae of Lorenzini electro-sensory cells, a duplication hotspot for crystallin genes conserved in jawed vertebrates, and a new metazoan clade of the Transient-receptor potential (TRP) family. These resources and results, obtained in an experimentally tractable chondrichthyan model, open new avenues to integrate multiomics analyses for the study of elasmobranchs and jawed vertebrates.

Dual RNAseq highlights the kinetics of skin microbiome and fish host responsiveness to bacterial infection.

BACKGROUND: Tenacibaculum maritimum is a fish pathogen known for causing serious damage to a broad range of wild and farmed marine fish populations worldwide. The recently sequenced genome of T. maritimum strain NCIMB 2154T provided unprecedented information on the possible molecular mechanisms involved in the virulence of this species. However, little is known about the dynamic of infection in vivo, and information is lacking on both the intrinsic host response (gene expression) and its associated microbiota. Here, we applied complementary omic approaches, including dual RNAseq and 16S rRNA gene metabarcoding sequencing using Nanopore and short-read Illumina technologies to unravel the host-pathogen interplay in an experimental infection system using the tropical fish Platax orbicularis as model. RESULTS: We showed that the infection of the host is characterised by an enhancement of functions associated with antibiotic and glucans catabolism functions but a reduction of sulfate assimilation process in T. maritimum. The fish host concurrently displays a large panel of immune effectors, notably involving innate response and triggering acute inflammatory response. In addition, our results suggest that fish activate an adaptive immune response visible through the stimulation of T-helper cells, Th17, with congruent reduction of Th2 and T-regulatory cells. Fish were, however, largely sensitive to infection, and less than 25% survived after 96 hpi. These surviving fish showed no evidence of stress (cortisol levels) or significant difference in microbiome diversity compared with controls at the same sampling time. The presence of T. maritimum in resistant fish skin and the total absence of any skin lesions suggest that these fish did not escape contact with the pathogen, but rather that some mechanisms prevented pathogens entry. In resistant individuals, we detected up-regulation of specific immune-related genes differentiating resistant individuals from controls at 96 hpi, which suggests a possible genomic basis of resistance, although no genetic variation in coding regions was found. CONCLUSION: Here we focus in detail on the interplay between common fish pathogens and host immune response during experimental infection. We further highlight key actors of defence response, pathogenicity and possible genomic bases of fish resistance to T. maritimum.

Fibroblast mitochondria in idiopathic Parkinson's disease display morphological changes and enhanced resistance to depolarization.

Mitochondrial dysfunction is a hallmark in idiopathic Parkinson's disease (IPD). Here, we established screenable phenotypes of mitochondrial morphology and function in primary fibroblasts derived from patients with IPD. Upper arm punch skin biopsy was performed in 41 patients with mid-stage IPD and 21 age-matched healthy controls. At the single-cell level, the basal mitochondrial membrane potential (Ψm) was higher in patients with IPD than in controls. Similarly, under carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone (FCCP) stress, the remaining Ψm was increased in patients with IPD. Analysis of mitochondrial morphometric parameters revealed significantly decreased mitochondrial connectivity in patients with IPD, with 9 of 14 morphometric mitochondrial parameters differing from those in controls. Significant morphometric mitochondrial changes included the node degree, mean volume, skeleton size, perimeter, form factor, node count, erosion body count, endpoints, and mitochondria count (all P-values < 0.05). These functional data reveal that resistance to depolarization was increased by treatment with the protonophore FCCP in patients with IPD, whereas morphometric data revealed decreased mitochondrial connectivity and increased mitochondrial fragmentation.

Construction and characterization of a BAC library for functional genomics in Xenopus tropicalis.

Large insert genomic DNA libraries are useful resources for genomic studies. Although the genome of Xenopus tropicalis stands as the amphibian reference genome because it benefitted from large-scale sequencing studies, physical mapping resources such as BAC libraries are lagging behind. Here we present the construction and characterization of a BAC library that covers the whole X. tropicalis genome. We prepared this BAC library from the genomic DNA of X. tropicalis females of the Adiopodoume strain. We characterized BAC clones by screening for specific loci, by chromosomal localization using FISH and by systematic BAC end sequencing. The median insert size is about 110kbp and the library coverage is around six genome equivalents. We obtained a total of 163,787 BAC end sequences with mate pairs for 77,711 BAC clones. We mapped all BAC end sequences to the reference X. tropicalis genome assembly to enable the identification of BAC clones covering specific loci. Overall, this BAC library resource complements the knowledge of the X. tropicalis genome and should further promote its use as a reference genome for developmental biology studies and amphibian comparative genomics.

Eating patterns and prevalence of obesity. Lessons learned from the Malaysian Food Barometer.

The Malaysian society is experiencing and coping with a fast modernization process, which is characterized by a rapid urbanization and rural exodus, an important reduction of the size of households, and the emergence of a new middle class. The Malaysian Food Barometer launched in 2013 has provided better understanding how these macro issues have affected the lifestyles and especially the food habits of the Malaysians. The country has indeed undergone a transition period from under-nutrition to over-nutrition in a few decades, with the prevalence of overweight and obesity having markedly and rapidly increased. A quantitative survey (n = 2000), elaborated from a qualitative preliminary phase, was carried out with the aim of analyzing the transformation of food habits at the national level. The present article focuses on the BMI issue in Malaysia, and investigates its relationships with the socio-demographic variables of the population, as well as their eating patterns. The mean BMI is 23.64 kg/m2, with 9.5% of the sample being obese, and 22% overweight. Strong statistical associations have been identified between BMI and independent variables such as size of the living area, ethnicity, level of education, gender, and age. Contrary to general believe, overweight and obesity were neither associated with the number of food intakes taken per day (including snacks) nor with the frequency of eating out. Nonetheless, obesity is over-represented in people who have dissonant eating behaviors, i.e. who declare having fewer food intakes a day (food norms) than they do actually (food practices). This process testifies that the Malaysians are experiencing a "food transition", which is linked with socio-economic development.

Exploring the genome of the salt-marsh Spartina maritima (Poaceae, Chloridoideae) through BAC end sequence analysis.

Spartina species play an important ecological role on salt marshes. Spartina maritima is an Old-World species distributed along the European and North-African Atlantic coasts. This hexaploid species (2n = 6x = 60, 2C = 3,700 Mb) hybridized with different Spartina species introduced from the American coasts, which resulted in the formation of new invasive hybrids and allopolyploids. Thus, S. maritima raises evolutionary and ecological interests. However, genomic information is dramatically lacking in this genus. In an effort to develop genomic resources, we analysed 40,641 high-quality bacterial artificial chromosome-end sequences (BESs), representing 26.7 Mb of the S. maritima genome. BESs were searched for sequence homology against known databases. A fraction of 16.91% of the BESs represents known repeats including a majority of long terminal repeat (LTR) retrotransposons (13.67%). Non-LTR retrotransposons represent 0.75%, DNA transposons 0.99%, whereas small RNA, simple repeats and low-complexity sequences account for 1.38% of the analysed BESs. In addition, 4,285 simple sequence repeats were detected. Using the coding sequence database of Sorghum bicolor, 6,809 BESs found homology accounting for 17.1% of all BESs. Comparative genomics with related genera reveals that the microsynteny is better conserved with S. bicolor compared to other sequenced Poaceae, where 37.6% of the paired matching BESs are correctly orientated on the chromosomes. We did not observe large macrosyntenic rearrangements using the mapping strategy employed. However, some regions appeared to have experienced rearrangements when comparing Spartina to Sorghum and to Oryza. This work represents the first overview of S. maritima genome regarding the respective coding and repetitive components. The syntenic relationships with other grass genomes examined here help clarifying evolution in Poaceae, S. maritima being a part of the poorly-known Chloridoideae sub-family.

Transcriptome de novo assembly from next-generation sequencing and comparative analyses in the hexaploid salt marsh species Spartina maritima and Spartina alterniflora (Poaceae).

Spartina species have a critical ecological role in salt marshes and represent an excellent system to investigate recurrent polyploid speciation. Using the 454 GS-FLX pyrosequencer, we assembled and annotated the first reference transcriptome (from roots and leaves) for two related hexaploid Spartina species that hybridize in Western Europe, the East American invasive Spartina alterniflora and the Euro-African S. maritima. The de novo read assembly generated 38 478 consensus sequences and 99% found an annotation using Poaceae databases, representing a total of 16 753 non-redundant genes. Spartina expressed sequence tags were mapped onto the Sorghum bicolor genome, where they were distributed among the subtelomeric arms of the 10 S. bicolor chromosomes, with high gene density correlation. Normalization of the complementary DNA library improved the number of annotated genes. Ecologically relevant genes were identified among GO biological function categories in salt and heavy metal stress response, C4 photosynthesis and in lignin and cellulose metabolism. Expression of some of these genes had been found to be altered by hybridization and genome duplication in a previous microarray-based study in Spartina. As these species are hexaploid, up to three duplicated homoeologs may be expected per locus. When analyzing sequence polymorphism at four different loci in S. maritima and S. alterniflora, we found up to four haplotypes per locus, suggesting the presence of two expressed homoeologous sequences with one or two allelic variants each. This reference transcriptome will allow analysis of specific Spartina genes of ecological or evolutionary interest, estimation of homoeologous gene expression variation using RNA-seq and further gene expression evolution analyses in natural populations.

Representations and practices of prevention in elderly populations: investigating acceptance to participate in and adhesion to an intervention study for the prevention of Alzheimer's disease (ACCEPT study)--the need for a multidisciplinary approach.

BACKGROUND: In the domain of Alzheimer's disease (AD) prevention, various potentially protective factors have been identified in epidemiological studies. Although the results of these observational studies have been relatively consistent, the results of intervention studies remain disappointing. Methodological problems could explain these negative results, like the selection of the population; a plausible assumption is that the older people who agree to take part in these intervention studies differ from those who refuse, and are those that are least likely to benefit from such programs. The aim of this study was (i) to study the determinants of participation in and adhesion to a prevention trial in a population of older individuals via a quantitative approach using a questionnaire, (ii) to study the representations and practices of prevention in this population using a qualitative approach using semi-structured interviews and focus groups. METHOD: The study population for the ACCEPT study was recruited at the time of inclusion of subjects in a prevention trial. The population was made up of persons aged 70 years or older, living at home and demonstrating some form of frailty, defined as a spontaneous memory complaint to their general practitioner or difficulties in carrying out instrumental activities of daily living. We used a quantitative approach based on the administration of a self-completed questionnaire sent to 1680 subjects having accepted to take part in the prevention trial, and to the sample of subjects meeting the inclusion criteria but having refused to take part. The qualitative approach, carried out at the moment of inclusion, involved subjects that having accepted to take part and subjects that having refused. Semi-structured interviews were carried out in order to understand the logic leading to refusal or acceptance. CONCLUSION: The analysis of the results will combine the viewpoints of the different disciplines. It will allow us to better understand the logic at work, to characterise the populations at risk of refusal, and perhaps to remove some of the barriers to participation in prevention programs. The identification of such barriers will provide feedback in terms of the conception and management of prevention measures.

Comparison of gene repertoires and patterns of evolutionary rates in eight aphid species that differ by reproductive mode.

In theory, the loss of sexual reproduction is expected to result in the accumulation of deleterious mutations. In aphids, two main types of life cycle, cyclic and obligate parthenogenesis, represent respectively "sexual" and "asexual" reproductive modes. We used the complete pea aphid genome and previously published expressed sequence tags (ESTs) from two other aphid species. In addition, we obtained 100,000 new ESTs from five more species. The final set comprised four sexual and four asexual aphid species and served to test the influence of the reproductive mode on the evolutionary rates of genes. We reconstructed coding sequences from ESTs and annotated these genes, discovering a novel peptide gene family that appears to be among the most highly expressed transcripts from several aphid species. From 203 genes found to be 1:1 orthologs among the eight species considered, we established a species tree that partly conflicted with taxonomy (for Myzus ascalonicus). We then used this topology to evaluate the dynamics of evolutionary rates and mutation accumulation in the four sexual and four asexual taxa. No significant increase of the nonsynonymous to synonymous ratio or of nonsynonymous mutation numbers was found in any of the four branches for asexual taxa. We however found a significant increase of the synonymous rate in the branch leading to the asexual species Rhopalosiphum maidis, which could be due to a change in the mutation rate or to an increased number of generations implied by its change of life cycle.

The transcriptome of the arbuscular mycorrhizal fungus Glomus intraradices (DAOM 197198) reveals functional tradeoffs in an obligate symbiont.

• The arbuscular mycorrhizal symbiosis is arguably the most ecologically important eukaryotic symbiosis, yet it is poorly understood at the molecular level. To provide novel insights into the molecular basis of symbiosis-associated traits, we report the first genome-wide analysis of the transcriptome from Glomus intraradices DAOM 197198. • We generated a set of 25,906 nonredundant virtual transcripts (NRVTs) transcribed in germinated spores, extraradical mycelium and symbiotic roots using Sanger and 454 sequencing. NRVTs were used to construct an oligoarray for investigating gene expression. • We identified transcripts coding for the meiotic recombination machinery, as well as meiosis-specific proteins, suggesting that the lack of a known sexual cycle in G. intraradices is not a result of major deletions of genes essential for sexual reproduction and meiosis. Induced expression of genes encoding membrane transporters and small secreted proteins in intraradical mycelium, together with the lack of expression of hydrolytic enzymes acting on plant cell wall polysaccharides, are all features of G. intraradices that are shared with ectomycorrhizal symbionts and obligate biotrophic pathogens. • Our results illuminate the genetic basis of symbiosis-related traits of the most ancient lineage of plant biotrophs, advancing future research on these agriculturally and ecologically important symbionts.

The THEMA study: a sociodemographic survey of hypercholesterolaemic individuals.

BACKGROUND: Hypercholesterolaemia is estimated to affect 20% of the population, although little sociodemographic information is available on affected individuals. The present study aimed to gather relevant information and investigate social determinants of dietary compliance. METHODS: A telephone survey was carried out on a representative population sample. Quotas were applied for gender, geography and degree of urbanisation. Individuals were eligible if they were hypercholesterolaemic, and were being followed by a doctor. Sociodemographic, socioeconomic and health data were collected, as well as information about the individuals' perception of the disease, their relationship and beliefs surrounding food, and their food behaviour (shopping, cooking, eating-out, deviation from prescribed diet). The association between compliance with diet and medication was investigated. RESULTS: Overall, 802 individuals were included, representing 8% of those contacted, as opposed to the expected 20%. Mean (SD) age was 60 (14.2) years, with 51% of individuals living as a couple; 48% had a good level of physical activity; 44% considered that the hypercholesterolaemia was inherited; 31% felt that the disease was normal beyond the age of 45 years. The functional and convivial aspects of eating were of more importance than that of health maintenance. Cheese was particularly likely to be eaten in dietary lapses. Of a subgroup of 729 individuals, 476 (65%) took medication; of these 476 individuals, 51% complied with dietary recommendations (P < 0.05). CONCLUSIONS: The key factors associated with dietary compliance in hypercholesterolaemic individuals were identified: age, sex, the perceptions of hypercholesterolaemia, and the sociocultural aspects of food. By contrast to general assumptions, both dietary and medicinal measures are practised fairly well by a large proportion of these individuals.

IANA task force on nutrition and cognitive decline with aging.

Cognitive impairment can be influenced by a number of factors. The potential effect of nutrition has become a topic of increasing scientific and public interest. In particular, there are arguments that nutrients (food and/or supplements) such as vitamins, trace minerals, lipids, can affect the risk of cognitive decline and dementia, especially in frail elderly people at risk of deficiencies. Our objective in this paper is to review data relating diet to risk of cognitive decline and dementia, especially Alzheimer's disease (AD). We chose to focus our statements on homocysteine-related vitamins (B-vitamins), antioxidant nutrients (vitamins E and C, carotenoids, flavonoids, enzymatic cofactors) and dietary lipids. Results of epidemiological studies may sometimes appeared conflicting; however, certain associations are frequently found. High intake of saturated and trans-unsaturated (hydrogenated) fats were positively associated with increased risk of AD, whereas intake of polyunsaturated and monounsaturated fats were protective against cognitive decline in the elderly in prospective studies. Fish consumption has been associated with lower risk of AD in longitudinal cohort studies. Moreover, epidemiologic data suggest a protective role of the B-vitamins, especially vitamins B9 and B12, on cognitive decline and dementia. Finally, the results on antioxidant nutrients may suggest the importance of having a balanced combination of several antioxidant nutrients to exert a significant effect on the prevention of cognitive decline and dementia, while taking into account the potential adverse effects of these nutrients. There is no lack of attractive hypotheses to support research on the relationships between nutrition and cognitive decline. It is important to stress the need to develop further prospective studies of sufficiently long duration, including subjects whose diet is monitored at a sufficiently early stage or at least before disease or cognitive decline exist. Meta analyses should be developed, and on the basis of their results the most appropriate interventional studies can be planned. These studies must control for the greatest number of known confounding factors and take into account the impact of the standard social determinants of food habits, such as the regional cultures, social status, and educational level.

[Topical silver sulfadiazine-induced acute renal failure]. / Insuffisance rénale aiguë après application topique de sulfadiazine argentique.

INTRODUCTION: Prolonged topical application of silver sulfadiazine cream can induce argyria and adverse effects of sulphonamides. We report a case of a woman with acute renal failure following repeated applications of topical silver sulfadiazine on pyoderma gangrenosum wounds. CASE REPORT: A 61 year-old woman suffering from rheumatoid arthritis, Sjogren's syndrome and scleroderma was treated with corticosteroids (1 mg/kg/day) and topical application of silver sulfadiazine cream (200 g/day) for extensive pyoderma gangrenosum wounds on the legs. Three weeks later, the patient was transferred to intensive care because of pulmonary edema, oligoanuria and disrupted consciousness. Laboratory data revealed leukopenia (1100/mm(3)) with neutropenia and renal failure (serum creatinine 316 micromol/l). Proteinuria was moderate and ultrasonography of the kidneys was normal. Silver concentration in blood was 1818 nmol/l (N < 92 nmol/l) and 1381 nmol/l (N < 9 nmol/l) in urine. Sulfadiazine concentration in blood was undetectable. All the signs regressed after withdrawal of silver sulfadiazine and after several sessions of hemodialysis. DISCUSSION: Various causes of renal failure are discussed in our patient. However, direct silver-induced renal toxicity is the most likely and is confirmed by the high concentration of silver in blood and urine and the improvement on withdrawal of the topical cream, without modification in the oral treatment. The absence of red corpuscles and crystals in the urine and undetectable concentrations of sulfadiazine in blood are not in favor of sulphonamide renal toxicity. Furthermore, the autoimmune diseases of our patient were well-controlled. Leukopenia could be secondary to silver sulfadiazine medullar toxicity. This observation confirms that this topical cream should not be used for long periods on extensive wounds.

[Should the prevention of obesity be demedicalised?]. / Faut-il démédicaliser la prévention de l'obésité?

Obesity prevalence is rapidly growing, particularly in children and young adolescents. It is proved to be important to prevent it within a public health strategy. Primary prevention of obesity should not be focused on obesity itself, but should be part of a global public health national policy, targeted to improve the nutritional status of the community, to reduce the risk for chronic diseases, to improve the health status and the quality of life of the general population. This overall prevention programme should be conducted on a large scale, at all level of the country infrastructure and sectors of society, and should acquired a strong local and regional support from communities, consumers and government, but it has also to be particularly focused on young subjects (and their family and school workers), especially in groups with low socio-economic status. Secondary prevention should be particularly focused on children with a high-risk for obesity and/or those with potential associated risk factors. Medical involvement is of a particular importance in this secondary prevention, to identify and to manage these at-risk children and young adolescents. The various approaches from a paediatrician, a physician specialised in human nutrition, a sociologist and a consumer representative are presented in this review.

The contemporary diet in France: "de-structuration" or from commensalism to "vagabond feeding".

Data collected from a sample of working individuals lunching at staff cafeterias were analysed to characterise contemporary food habits in terms of meal structure, eating outside meals, and other aspects of the organization of the daily food intake. Discrepancies were found between individuals' ideas of a proper meal and their actual practices. This brings to light some contradictions between conceptions underlying the contemporary diet and the more traditional idea of a structured meal. Analysis of the eater's search for a balanced diet from a cultural and historical viewpoint opens avenues of research common to both the social sciences and food science.

[Phenylbutazone-induced sialadenitis fever simulating angioedema]. / Sialadénite à la phénylbutazone simulant un oedème de Quincke.

BACKGROUND: Drug-induced sialadenitis is uncommon and unrecognized. Drugs such as nitrofurantoïn, nifedipine and methimazole have been reported to induce sialadenitis. However, phenylbutazone and oxyphenbutazone are the most frequently implicated agents. We describe a case of phenylbutazone-induced parotitis and submaxillitis with cutaneous and hepatic involvement. CASE REPORT: A 51 year-old woman who had received phenylbutazone for the past 6 days was hospitalized for diagnosis of Quincke's oedema. Clinical examination in fact revealed bilateral parotitis and submaxillitis. The patient had contracted mumps in infancy. Improvement was noticed 8 days after stopping the drug and treatment by glucocorticosteroid. Nevertheless a pruritic eruption with fever appeared. Laboratory data showed leukocytosis with neutrophilia, ESR of 75 mm/hr, hepatic cholestasis and cytolysis. Infectious and autoimmune causes were ruled out. The eruption spontaneously disappeared after 5 days. Laboratory studies 3 weeks later were normal. DISCUSSION: Quincke's edema diagnosis had been established too fast on "allergic past history" and patient interrogation. Complete clinical examination revealed the correct diagnosis of sialadenitis. This observation shows similarities with other publications: unbearable xerostomia appearing before sialadenitis and with a long course, parotitis with sub-maxillitis, 6 days delay after the first administration of phenylbutazone before fever, local evolution without complication, inflammatory biological syndrome with neutrophilia and absence of infectious cause. Pruritic maculo-papulous eruption and biological hepatic abnormalities are however rare. An hypersensibility mechanism is discussed.

Nuevos y viejos antipsicóticos / New and old antipsychotics

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[Genital leiomyomas of the male nipple: two cases]. / Léiomyome dartoïque du mamelon: deux cas chez l'homme.

BACKGROUND: Genital leiomyoma is a rare benign solitary skin tumor, not painful, developed from smooth muscle. Genital leiomyoma arising from the nipple is extremely rare, especially in males. CASES REPORT: A 47 year-old male had a 2 cm cutaneous plaque with nodules located on the right nipple. This plaque was circumscribed, erythematous, pruriginous and was not painful. The lesion had been noticed by the patient two years ago. A 37 year-old male showed a 1.5 cm cutaneous plaque located on the left nipple. The plaque was slightly erythematous, pruriginous, not painful and had been noticed by the patient 5 years earlier. Histology provided the diagnosis of genital leiomyoma in both cases. No surgical therapy was performed. DISCUSSION: Cutaneous leiomyomas are classified in 3 types regarding their origin: multiple or solitary piloleiomyoma, arising from arectores pilorum muscles, solitary genital leiomyoma, arising from the dartoic, vulvar, or mammillary muscles, and solitary angioleiomyoma, arising from the vein muscles. Clinically, genital leiomyoma is a 1 cm diameter solitary erythematous, firm nodule. According to many authors, genital leiomyoma is asymptomatic, but in the 2 patients, the lesions were pruriginous. Surgical excision is usually performed.

[Plaque variant of trichoblastic fibroma]. / Fibrome trichoblastique en plaque.

BACKGROUND: Tricoblastic fibroma is a rare benign skin tumor originating in the hair follicle. There are two clinical presentations: nodular and plaque variants. The plaque variant is almost exclusively located on the face with deep tissue infiltration. CASE REPORT: A 38-year-old man presented with a 2 cm diameter cutaneous plaque located on the right cheek. It had first been noted by the patient 3 years earlier and had enlarged slowly. On examination, the plaque was well defined, yellowish and slightly indurated. The first clinical diagnosis was basal cell carcinoma and the plaque was removed. Histology provided the diagnosis of trichoblastic fibroma. The patient remains well, with no evidence of recurrence, 10 months after excision. DISCUSSION: Trichoblastoma is an inclusive term for all benign cutaneous neoplasms that are mostly composed of follicular germinative cells. According to Altman, the plaque variant of trichoblastic fibroma is a poorly circumscribed neoplasm, particularly at its lateral and deep margins. This author also states that mitotic figures are more numerous in the plaque variant of trichoblastic fibroma and considers this clinical variant as a low-grade follicular malignancy.