395 resultados para PIGMENTED VILLONODULAR SYNOVITIS


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Congenital naevi of the melanocytic system include numerous types, which differ in their clinical appearance, pattern of distribution, and histopathological features (1). Examples are large congenital melanocytic naevus, macular naevus spilus, papular naevus spilus, café-au-lait macules of neurofibromatosis 1, café-au-lait macules arranged in broad bands as noted in McCune-Albright syndrome, partial unilateral lentiginosis, naevus achromicus (naevus depigmentosus), phylloid hypermelanosis, and phylloid hypomelanosis (1–3). We describe here two patients with a systematized pigmentary naevus that differed from all naevi reported so far.

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Molecular techniques can aid in the classification of Biomphalaria species because morphological differentiation between these species is difficult. Previous studies using phylogeny, morphological and molecular taxonomy showed that some populations studied were Biomphalaria cousini instead of Biomphalaria amazonica. Three different molecular profiles were observed that enabled the separation of B. amazonica from B. cousini. The third profile showed an association between the two and suggested the possibility of hybrids between them. Therefore, the aim of this work was to investigate the hybridism between B. cousini and B. amazonica and to verify if the hybrids are susceptible to Schistosoma mansoni. Crosses using the albinism factor as a genetic marker were performed, with pigmented B. cousini and albino B. amazonica snails identified by polymerase chain reaction-restriction fragment length polymorphism. This procedure was conducted using B. cousini and B. amazonica of the type locality accordingly to Paraense, 1966. In addition, susceptibility studies were performed using snails obtained from the crosses (hybrids) and three S. mansoni strains (LE, SJ, AL). The crosses between B. amazonica and B. cousini confirmed the occurrence of hybrids. Moreover, hybrids can be considered potential hosts of S. mansoni because they are susceptible to LE, SJ and AL strains (4.4%, 5.6% and 2.2%, respectively). These results indicate that there is a risk of introducing schistosomiasis mansoni into new areas.

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The numerical keratinocyte to melanocyte relation was studied in café au lait spots and adjacent normally pigmented skin of 9 patients with classical neurofibromatosis. Compared to normal skin of healthy individuals, the keratinocyte:melanocyte ratio distributions obtained in neurofibromatosis indicated a shift to lower values in the biopsies of café au lait spots and normally pigmented skin. These results are evidence in favor of an impaired tissue organization of the epidermis in neurofibromatosis with regard to the keratinocyte-melanocyte interrelation.

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OBJECTIVE: There are controversies regarding the pro-angiogenic activity of placental growth factor (PGF) in diabetic retinopathy (DR). For a better understanding of its role on the retina, we have evaluated the effect of a sustained PGF over-expression in rat ocular media, using ciliary muscle electrotransfer (ET) of a plasmid encoding rat PGF-1 (pVAX2-rPGF-1). MATERIALS AND METHODS: pVAX2-rPGF-1 ET in the ciliary muscle (200 V/cm) was achieved in non diabetic and diabetic rat eyes. Control eyes received saline or naked plasmid ET. Clinical follow up was carried out over three months using slit lamp examination and fluorescein angiography. After the control of rPGF-1 expression, PGF-induced effects on retinal vasculature and on the blood-external barrier were evaluated respectively by lectin and occludin staining on flat-mounts. Ocular structures were visualized through histological analysis. RESULTS: After fifteen days of rPGF-1 over-expression in normal eyes, tortuous and dilated capillaries were observed. At one month, microaneurysms and moderate vascular sprouts were detected in mid retinal periphery in vivo and on retinal flat-mounts. At later stages, retinal pigmented epithelial cells demonstrated morphological abnormalities and junction ruptures. In diabetic retinas, PGF expression rose between 2 and 5 months, and, one month after ET, rPGF-1 over-expression induced glial activation and proliferation. CONCLUSION: This is the first demonstration that sustained intraocular PGF production induces vascular and retinal changes similar to those observed in the early stages of diabetic retinopathy. PGF and its receptor Flt-1 may therefore be looked upon as a potential regulatory target at this stage of the disease.

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A quasi-defined medium that supports the growth of Streptococcus agalactiae as pigmented colonies has been developed. The medium contains starch, a peptic digest of albumin, amino acids, nucleosides, vitamins, and salts. The presence of free cysteine, which could be replaced with other sulphur-containing compounds and to a lesser degree by reducing agents, was required for pigment formation.

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BACKGROUND: Indocyanine green video-angiography (ICG) is a recent examination technique, its possibilities and limitations as far as intraocular tumours are concerned, haven't been fully explored yet. MATERIAL AND METHODS: We have studied 50 cases of non-pigmented choroidal tumours, including 14 cases of choroidal hemangioma's, 11 cases of posterior uveal metastases and 25 cases of non-pigmented melanoma's. RESULTS: Characteristic images were obtained when examining choroidal hemangioma's and, until a certain point, posterior choroidal metastases. Non pigmented melanoma's on the contrary, presented a great variety of different indocyanine green angiographic pictures. CONCLUSION: Indocyanine green video-angiography (ICG) has a definite value in the differential diagnosis of non-pigmented posterior choroidal tumours.

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PURPOSE: The objective of this study was to evaluate the long-term safety and pharmacokinetic profile of a dexamethasone-loaded poly-epsilon-caprolactone (PCL) intravitreous implant. METHODS: The PCL devices were prepared by compression and were inserted into the vitreous of pigmented rabbits. At different time points, vitreous samples were retrieved, and dexamethasone concentration was analyzed by high-performance liquid chromatography. The biodegradation of the implants was evaluated by scanning electron microscopy, and the dexamethasone remaining was evaluated at the end of follow-up. Clinical and histologic examinations were performed to evaluate the implant's tolerance. RESULTS: The PCL implant allows for a controlled and prolonged delivery of dexamethasone in rabbits eyes since it released the drug within the therapeutic range for at least 55 weeks. At 55 weeks approximately 79% of the drug was still present in the implant. Biodegradation study showed that PCL implants degradation is very slow. Clinical and histologic observations showed that the devices were very well tolerated in the rabbit eye. CONCLUSIONS: This study demonstrates the feasibility and tolerance of intravitreous PCL drug delivery systems, which can offer a wide range of applications for intraocular drug delivery because of their controlled and prolonged release over months or even years.

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Appropriate curing is important for concrete to obtain the designed properties. This research was conducted to evaluate the curing effects of different curing materials and methods on pavement properties. At present the sprayed curing compound is a common used method for pavement and other concrete structure construction. Three curing compounds were selected for testing. Two different application rates were employed for the white-pigmented liquid curing compounds. The concrete properties of temperature, moisture content, conductivity, and permeability were examined at several test locations. It was found, in this project, that the concrete properties varied with the depth. Of the tests conducted (maturity, sorptivity, permeability, and conductivity), conductivity appears to be the best method to evaluate the curing effects in the field and bears potential for field application. The results indicated that currently approved curing materials in Iowa, when spread uniformly in a single or double application, provide adequate curing protection and meet the goals of the Iowa Department of Transportation. Experimental curing methods can be compared to this method through the use of conductivity testing to determine their application in the field.

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Purpose: Melastatin (MLSN-1) belongs to the transient receptor potential (TRP) superfamilly of calcium-permeable channels, and has been reported to be a melanocyte-specific gene. In human cutaneous melanoma, MLSN-1 mRNA expression displays a pattern of inverse correlation to disease free survival. We describe the patterns of MLSN-1 mRNA expression in conjunctival nevi, conjunctival melanoma, and uveal melanoma. Methods: In situ hybridization using two S35-labelled riboprobes for MLSN-1 was performed on formalin-fixed, paraffin-embedded tissues. A control probe for H4 histone was used to confirm mRNA integrity in these archival tissues. The 21 ocular melanocytic lesions studied included 5 conjunctival nevi, 6 conjunctival melanomas, and 10 enucleated eyes with uveal melanoma. The minimal requirement for interpretation of MLSN-1 mRNA loss was the presence of only background signal in a focus of at least 5 adjacent melanocytic cells. Results: Ubiquitous expression of MLSN-1 mRNA was found in conjunctival melanocytes in the non-lesional epithelium adjacent to the conjunctival melanocytic proliferations and in all 5 conjunctival nevi studied. Four different patterns of MLSN-1 mRNA expression were observed in conjunctival melanomas: one case showed complete preservation of MLSN-1 mRNA, two cases showed diffuse scattered loss of MLSN-1 mRNA, two cases showed focal clonal loss of MLSN-1 mRNA expression, and one case had no detected MLSN-1 mRNA. In uveal melanomas, MLSN-1 mRNA expression was partially preserved in two cases, lost by a clearly delimited subset of tumor cells (focal clonal loss) in four cases, and was not detectable in the entire tumor in four cases. MLSN-1 mRNA expression was also found in the normal iris, ciliary and choroidal melanocytes as well as in the retinal pigmented epithelium and in the inner nuclear layer of the retina. Conclusions: The patterns of MLSN-1 mRNA expression in the ocular melanocytic proliferations are similar to those reported in cutaneous melanocytic proliferations. In the conjunctiva, MLSN-1 mRNA expression appeared to correlate with tumor progression; all the benign conjunctival nevi had preserved expression of MLSN-1 mRNA and most of the conjunctival melanomas partial or complete loss of expression. In uveal melanoma, patterns of melastatin expression ranging from partial preservation to complete loss were found. Additional studies of a large number of ocular melanocytic proliferations may show a correlation with tumor progression and prognosis similar to that observed in cutaneous melanoma.

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Purpose: Pathologic choroidal neovascularizations (CNV) are implicated in the wet form of age-related macular degeneration (ARMD). Abnormal vessel growth is also observed in disease when hypoxia and/or inflammation occur. Our goal is to establish a standard protocol of laser-induced CNV in mice that have different levels of pigmentation to identify the most reliable animal model.Methods: CNV was induced by 4 burns around the optic disk, using a green argon laser (100μm diameter spot size; 0,05 sec. duration) in C57/Bl6, DBA/1 and Balb/c to ascertain the efficacy of the method in function of retina pigmentation. Five different intensities were tested and Bruch's membrane disruption was identified by the appearance of a bubble at the site of photocoagulation. Fluorescein angiographies (FA) were undertaken 14 days post lesion and CNV area was quantified by immunohistochemistry on cryosections.Results: CNV retina area was related to spot intensity after laser injury. While 180mW and 200mW do not induce reliable CNV (respectively 27.85±0.35% and 29±1.67% of the retina surface), 260mW is required to induce 51,07±8.52% of CNV in C57/Bl6 mice. For the DBA/1 strain, less pigmented, 200mW was sufficient to induce 49.35±3.9% of CNV, indicating that lower intensity are required to induce CNV. Furthermore, an intensity of 180mW induced greater CNV (35.55±6.01%) than in C57/Bl6 mice. Nevertheless, laser did not induce reproducible 50% CNV in Balb/c albino mice for all intensities tested. Isolectin-B4 and GFAP stainings revealed neovessel formation and photoreceptor (PR) degeneration at the impact site. The presence of glia was observed throughout all the retinal layers and angiograms showed fluorescein leakage in pigmented mice.Conclusions: The establishment of a standard protocol to induce CNV and subsequent PR degeneration is of prime importance for the use of the laser-induced CNV model and will allow to evaluate the therapeutic potency of agents to prevent CNV and retinal degeneration.

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OBJECTIVES: To determine clinical and ultrasonographic predictors of joint replacement surgery across Europe in primary osteoarthritis (OA) of the knee. METHODS: This was a 3-year prospective study of a painful OA knee cohort (from a EULAR-sponsored, multicentre study). All subjects had clinical evaluation, radiographs and ultrasonography (US) at study entry. The rate of knee replacement surgery over the 3-year follow-up period was determined using Kaplan-Meier survival data analyses. Predictive factors for joint replacement were identified by univariate log-rank test then multivariate analysis using a Cox proportional-hazards regression model. Potential baseline predictors included demographic, clinical, radiographic and US features. RESULTS: Of the 600 original patients, 531 (88.5%), mean age 67+/-10 years, mean disease duration 6.1+/-6.9 years, had follow-up data and were analysed. During follow-up (median 3 years; range 0-4 years), knee replacement was done or required for 94 patients (estimated event rate of 17.7%). In the multivariate analysis, predictors of joint replacement were as follows: Kellgren and Lawrence radiographic grade (grade > or =III vs <III, hazards ratio (HR) = 4.08 (95% CI 2.34 to 7.12), p<0.0001); ultrasonographic knee effusion (> or =4 mm vs <4 mm) (HR = 2.63 (95% CI 1.70 to 4.06), p<0.0001); knee pain intensity on a 0-100 mm visual analogue scale (> or =60 vs <60) (HR = 1.81 (95% CI 1.15 to 2.83), p=0.01) and disease duration (> or =5 years vs <5 years) (HR=1.63 (95% CI 1.08 to 2.47), p=0.02). Clinically detected effusion and US synovitis were not associated with joint replacement in the univariate analysis. CONCLUSION: Longitudinal evaluation of this OA cohort demonstrated significant progression to joint replacement. In addition to severity of radiographic damage and pain, US-detected effusion was a predictor of subsequent joint replacement.

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SUMMARY IN FRENCH Les cellules souches sont des cellules indifférenciées capables a) de proliférer, b) de s'auto¬renouveller, c) de produire des cellules différenciées, postmitotiques et fonctionnelles (multipotencialité), et d) de régénérer le tissu après des lésions. Par exemple, les cellules de souches hematopoiétiques, situées dans la moelle osseuse, peuvent s'amplifier, se diviser et produire diverses cellules différenciées au cours de la vie, les cellules souches restant dans la moelle osseuse et consentant leur propriété. Les cellules souches intestinales, situées dans la crypte des microvillosités peuvent également régénérer tout l'intestin au cours de la vie. La rétine se compose de six classes de neurones et d'un type de cellule gliale. Tous ces types de cellules sont produits par un progéniteur rétinien. Le pic de production des photorécepteurs se situe autour des premiers jours postnatals chez la souris. A cette période la rétine contient les cellules hautement prolifératives. Dans cette étude, nous avons voulu analyser le phénotype de ces cellules et leur potentiel en tant que cellules souches ou progénitrices. Nous nous sommes également concentrés sur l'effet de certains facteurs épigéniques sur leur destin cellulaire. Nous avons observé que toutes les cellules prolifératives isolées à partir de neurorétines postnatales de souris expriment le marqueur de glie radiaire RC2, ainsi que des facteurs de transcription habituellement trouvés dans la glie radiaire (Mash1, Pax6), et répondent aux critères des cellules souches : une capacité élevée d'expansion, un état indifférencié, la multipotencialité (démontrée par analyse clonale). Nous avons étudié la différentiation des cellules dans différents milieux de culture. En l'absence de sérum, l'EGF induit l'expression de la β-tubulin-III, un marqueur neuronal, et l'acquisition d'une morphologie neuronale, ceci dans 15% des cellules présentes. Nous avons également analysé la prolifération de cellules. Seulement 20% des cellules incorporent le bromodéoxyuridine (BrdU) qui est un marqueur de division cellulaire. Ceci démontre que l'EGF induit la formation des neurones sans une progression massive du cycle cellulaire. Par ailleurs, une stimulation de 2h d'EGF est suffisante pour induire la différentiation neuronale. Certains des neurones formés sont des cellules ganglionnaires rétiniennes (GR), comme l'indique l'expression de marqueurs de cellules ganglionnaires (Ath5, Brn3b et mélanopsine), et dans de rare cas d'autres neurones rétiniens ont été observés (photorécepteurs (PR) et cellules bipolaires). Nous avons confirmé que les cellules souches rétiniennes tardives n'étaient pas restreintes au cours du temps et qu'elles conservent leur multipotencialité en étant capables de générer des neurones dits précoces (GR) ou tardifs (PR). Nos résultats prouvent que l'EGF est non seulement un facteur contrôlant le développement glial, comme précédemment démontré, mais également un facteur efficace de différentiation pour les neurones rétiniens, du moins in vitro. D'autre part, nous avons voulu établir si l'oeil adulte humain contient des cellules souches rétiniennes (CSRs). L'oeil de certains poissons ou amphibiens continue de croître pendant l'âge adulte du fait de l'activité persistante des cellules souches rétiniennes. Chez les poissons, le CSRs se situe dans la marge ciliaire (CM) à la périphérie de la rétine. Bien que l'oeil des mammifères ne se développe plus pendant la vie d'adulte, plusieurs groupes ont prouvé que l'oeil de mammifères adultes contient des cellules souches rétiniennes également dans la marge ciliaire plus précisément dans l'épithélium pigmenté et non dans la neurorétine. Ces CSRs répondent à certains critères des cellules souches. Nous avons identifié et caractérisé les cellules souches rétiniennes résidant dans l'oeil adulte humain. Nous avons prouvé qu'elles partagent les mêmes propriétés que leurs homologues chez les rongeurs c.-à-d. auto-renouvellement, amplification, et différenciation en neurones rétiniens in vitro et in vivo (démontré par immunocoloration et microarray). D'autre part, ces cellules peuvent être considérablement amplifiées, tout en conservant leur potentiel de cellules souches, comme indiqué par l'analyse de leur profil d'expression génique (microarray). Elles expriment également des gènes communs à diverses cellules souches: nucleostemin, nestin, Brni1, Notch2, ABCG2, c-kit et son ligand, aussi bien que cyclin D3 qui agit en aval de c-kit. Nous avons pu montré que Bmi1et Oct4 sont nécessaires pour la prolifération des CSRs confortant leur propriété de cellules souches. Nos données indiquent que la neurorétine postnatale chez la souris et l'épithélium pigmenté de la marge ciliaire chez l'humain adulte contiennent les cellules souches rétiniennes. En outre, nous avons développé un système qui permet d'amplifier et de cultiver facilement les CSRs. Ce modèle permet de disséquer les mécanismes impliqués lors de la retinogenèse. Par exemple, ce système peut être employé pour l'étude des substances ou des facteurs impliqués, par exemple, dans la survie ou dans la génération des cellules rétiniennes. Il peut également aider à disséquer la fonction de gènes ou les facteurs impliqués dans la restriction ou la spécification du destin cellulaire. En outre, dans les pays occidentaux, la rétinite pigmentaire (RP) touche 1 individu sur 3500 et la dégénérescence maculaire liée à l'âge (DMLA) affecte 1 % à 3% de la population âgée de plus de 60 ans. La génération in vitro de cellules rétiniennes est aussi un outil prometteur pour fournir une source illimitée de cellules pour l'étude de transplantation cellulaire pour la rétine. SUMMARY IN ENGLISH Stem cells are defined as undifferentiated cells capable of a) proliferation, b) self maintenance (self-renewability), c) production of many differentiated functional postmitotic cells (multipotency), and d) regenerating tissue after injury. For instance, hematopoietic stem cells, located in bone marrow, can expand, divide and generate differentiated cells into the diverse lineages throughout life, the stem cells conserving their status. In the villi crypt, the intestinal stem cells are also able to regenerate the intestine during their life time. The retina is composed of six classes of neurons and one glial cell. All these cell types are produced by the retinal progenitor cell. The peak of photoreceptor production is reached around the first postnatal days in rodents. Thus, at this stage the retina contains highly proliferative cells. In our research, we analyzed the phenotype of these cells and their potential as possible progenitor or stem cells. We also focused on the effect of epigenic factor(s) and cell fate determination. All the proliferating cells isolated from mice postnatal neuroretina harbored the radial glia marker RC2, expressed transcription factors usually found in radial glia (Mash 1, Pax6), and met the criteria of stem cells: high capacity of expansion, maintenance of an undifferentiated state, and multipotency demonstrated by clonal analysis. We analyzed the differentiation seven days after the transfer of the cells in different culture media. In the absence of serum, EGF led to the expression of the neuronal marker β-tubulin-III, and the acquisition of neuronal morphology in 15% of the cells. Analysis of cell proliferation by bromodeoxyuridine incorporation revealed that EGF mainly induced the formation of neurons without stimulating massively cell cycle progression. Moreover, a pulse of 2h EGF stimulation was sufficient to induce neuronal differentiation. Some neurons were committed to the retinal ganglion cell (RGC) phenotype, as revealed by the expression of retinal ganglion markers (Ath5, Brn3b and melanopsin), and in few cases to other retinal phenotypes (photoreceptors (PRs) and bipolar cells). We confirmed that the late RSCs were not restricted over-time and conserved multipotentcy characteristics by generating retinal phenotypes that usually appear at early (RGC) or late (PRs) developmental stages. Our results show that EGF is not only a factor controlling glial development, as previously shown, but also a potent differentiation factor for retinal neurons, at least in vitro. On the other hand, we wanted to find out if the adult human eye contains retina stem cells. The eye of some fishes and amphibians continues to grow during adulthood due to the persistent activity of retinal stem cells (RSCs). In fish, the RSCs are located in the ciliary margin zone (CMZ) at the periphery of the retina. Although, the adult mammalian eye does not grow during adult life, several groups have shown that the adult mouse eye contains retinal stem cells in the homologous zone (i.e. the ciliary margin), in the pigmented epithelium and not in the neuroretina. These RSCs meet some criteria of stem cells. We identified and characterized the human retinal stem cells. We showed that they posses the same features as their rodent counterpart i.e. they self-renew, expand and differentiate into retinal neurons in vitro and in vivo (indicated by immunostaining and microarray analysis). Moreover, they can be greatly expanded while conserving their sternness potential as revealed by the gene expression profile analysis (microarray approach). They also expressed genes common to various stem cells: nucleostemin, nestin, Bmil , Notch2, ABCG2, c-kit and its ligand, as well as cyclin D3 which acts downstream of c-kit. Furthermore, Bmil and Oct-4 were required for RSC proliferation reinforcing their stem cell identity. Our data indicate that the mice postnatal neuroretina and the adult pigmented epithelium of adult human ciliary margin contain retinal stem cells. We developed a system to easily expand and culture RSCs that can be used to investigate the retinogenesis. For example, it can help to screen drugs or factors involved, for instance, in the survival or generation of retinal cells. This could help to dissect genes or factors involved in the restriction or specification of retinal cell fate. In Western countries, retinitis pigmentosa (RP) affects 1 out of 3'500 individuals and age-related macula degeneration (AMD) strikes 1 % to 3% of the population over 60. In vitro generation of retinal cells is thus a promising tool to provide an unlimited cell source for cellular transplantation studies in the retina.

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The case of a 2-month-old healthy infant without relevant medical history. The patient was referred due to the aggravation of a swelling occupying the left half of the anterior maxilla. This lesion became visible approximately one month ago; it involved the buccal gingiva and alveolar bone, including the deciduous tooth germs 6.1 and 6.2. The swelling had dimensions of 20 mm x 20 mm. The surgical excision was performed under general anesthesia. The tooth buds of 6.1 and 6.2 were closely related to the tumour and so were removed. The lesion was entirely enucleated. The pathology of the lesion confirmed a melanotic neuroectodermal tumour of infancy. The melanotic neuroectodermal tumour of infancy (MNTI) has been described as a rare benign pigmented painless swelling that usually occurs in the anterior region of the maxilla and in the incisor region. The histological examination showed small basophilic cells, many containing melanin pigmentation within the cytoplasm, with a second population of larger cubical cells with abundant cytoplasm, arranged in alveolar or adenoid clusters. According to Krompecher this tumour derives from epithelial nests evolved at the time of embryonic fusion of the facial processes. It has also been suggested that the tumour arises from the retinal anlage by a pinching-off process of neuroepithelium during the formation of embryonic eye. More recently, the presence of high levels of vanillylmandelic acid suggest a neural origin of the tumour.

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A clinicopathologic case of an 80-year-old male patient with a single cutaneous tumor on the upper part of the left eyelid is reported. It was a grayish and pigmented mass covered with a thick keratin layer, well circumscribed, and exophytic. After surgical removal, histopathology showed that the tumor had a papillomatous pattern and was growing under a thick layer of hyperkeratosis. It was a typical squamous cell papilloma. This tumor belongs to the benign eyelid tumor group and can be found on the eyelids of elderly people.