Immunohistochemical expression of melan-A and tyrosinase in uveal melanoma

BACKGROUND: Melan-A and tyrosinase are new immunohistochemical markers that can be used in the diagnosis of melanocytic lesions. The aim of this study was to investigate the correlation between radiotherapy or clinicohistopathological parameters and the expression of melan-A and tyrosinase in uveal melanoma. METHODS: Thirty-six enucleated cases of uveal melanoma were studied. The formalin-fixed, paraffin-embedded specimens were immunostained with monoclonal antibodies against melan-A and tyrosinase. The samples were classified as either positive or negative. The chi-square or the Student-t tests were used to test for the correlation of the expression rates of melan-A and tyrosinase with clinico-pathological parameters. RESULTS: Melan-A and tyrosinase were positive in 33 (91.7%) and 35 (97.2%) of the specimens, respectively. There was no significant association between the expression of melan-A or tyrosinase and radiotherapy or any clinico-pathological parameter. All specimens were positive for at least one of the immunohistochemical markers. CONCLUSION: To the best of our knowledge this is the first study concluding that the expression of melanocytic markers such as melan-A and tyrosinase is not influenced by radiotherapy or any clinico-pathological parameter. Moreover, when tyrosinase and melan-A are used together, 100% of the formalin-fixed, paraffin-embedded uveal melanoma samples tested positive for one of those markers

Clinical-histopathological correlation in a case of Coats' disease

Background: Coats' disease is a non-hereditary ocular disease, with no systemic manifestation, first described by Coats in 1908. It occurs more commonly in children and has a clear male predominance. Most patients present clinically with unilateral decreased vision, strabismus or leukocoria. the most important differential diagnosis is unilateral retinoblastoma, which occurs in the same age group and has some overlapping clinical manifestations.Case presentation: A 4 year-old girl presented with a blind and painful right eye. Ocular examination revealed neovascular glaucoma, cataract and posterior synechiae. Although viewing of the fundus was impossible, computed tomography disclosed total exsudative retinal detachment in the affected eye. the eye was enucleated and subsequent histopathological evaluation confirmed the diagnosis of Coats' disease.Conclusion: General pathologists usually do not have the opportunity to receive and study specimens from patients with Coats' disease. Coats' disease is one of the most important differential diagnoses of retinoblastoma. Therefore, It is crucial for the pathologist to be familiar with the histopathological features of the former, and distinguish it from the latter.McGill Univ, Ctr Hlth, Dept Ophthalmol & Pathol, Montreal, PQ, CanadaHenry C Witelson Ocular Pathol Lab, Montreal, PQ, CanadaUniversidade Federal de São Paulo, EPM, Dept Ophthalmol, UNIFESP, São Paulo, BrazilHosp Servidores Estado, Dept Ophthalmol, Rio de Janeiro, BrazilUniversidade Federal de São Paulo, EPM, Dept Ophthalmol, UNIFESP, São Paulo, BrazilWeb of Scienc

Expression of EpCAM in uveal melanoma

BACKGROUND: Uveal melanoma (UM) is the most common primary intraocular malignant tumor in adults, and nearly 40% of UM will develop metastasis that will ultimately lead to death. The Epithelial Cell Adhesion Molecule (EpCAM) is a type I transmembrane glycoprotein expressed by carcinomas of head and neck, ovary, colon, breast, kidney and lung. Recently, antibodies against EpCAM such as Edrecolomab and Catumaxomab were developed, and clinical trials with these antibodies have been used in several types of neoplasia. We studied the expression of EpCAM in UM. METHODS: 25 enucleated formalin-fixed, paraffin-embedded UM specimens were immunostained for EpCAM. Histopathological analysis of the specimens with regards to prognostic factors such as cell type, largest (linear) tumor dimension, number of mitotic figures, scleral invasion and tumor infiltrating lymphocytes were done. RESULTS: None of them was positive for this EpCAM. CONCLUSION: In our report, UM did not express EpCAM. Therefore, it is not a helpful immunohistochemical marker to predict the behavior of UM. Further studies are needed to verify if EpCAM could also be related with prognosis and treatment of UM

The role of c-kit and imatinib mesylate in uveal melanoma

BACKGROUND: Uveal melanoma (UM) is the most common primary intraocular tumor in adults, leading to metastasis in 40% of the cases and ultimately to death in 10 years, despite local and/or systemic treatment. The c-kit protein (CD117) is a membrane-bound tyrosine kinase receptor and its overexpression has been observed in several neoplasms. Imatinib mesylate is a FDA approved compound that inhibits tyrosine quinase receptors, as well as c-kit. Imatinib mesylate controls tumor growth in up to 85% of advanced gastrointestinal stromal tumors, a neoplasia resistant to conventional therapy. METHODS: Fifty-five specimens of primary UM selected from the archives of the Ocular Pathology Laboratory, McGill University, Montreal, Canada, were immunostained for c-kit. All cells displaying distinct immunoreactivity were considered positive. Four human UM cell lines and 1 human uveal transformed melanocyte cell line were tested for in vitro proliferation Assays (TOX-6) and invasion assay with imatinib mesylate (concentration of 10 μM). RESULTS: The c-kit expression was positive in 78.2% of the UM. There was a statistical significant decrease in the proliferation and invasion rates of all 5 cell lines. CONCLUSION: The majority of UM expressed c-kit, and imatinib mesylate does decrease the proliferation and invasion rates of human UM cell lines. These results justify the need for a clinical trial to investigate in vivo the response of UM to imatinib mesylate

Histopathological study of lesions of the caruncle: a 15-year single center review

<p>Abstract</p> <p>Introduction</p> <p>The caruncle is a modified cutaneous tissue located at the inner canthus that contains hair follicles, accessory lacrimal glands, sweat glands and sebaceous glands. These different types of tissues can give rise to a wide variety of lesions that make the clinical diagnosis difficult. The aim of the study was to investigate the most common types of caruncle lesions and the clinical and pathological correlation.</p> <p>Methods</p> <p>Retrospective, observational case series. Records of caruncle lesions examined at the Henry C. Witelson Ocular Pathology Laboratory, McGill University, Montreal, Canada, between 1993 and 2008 were analyzed, comparing the clinical and histopathological findings.</p> <p>Results</p> <p>A total of 42 lesions from 42 patients were analyzed. Twenty-six (61.90%) of the patients were women and 16 (38.10%) were men and the age range from 20 to 84. The main diagnoses were: 16 epithelial lesions (38.09%), 14 inflammatory lesions (31.70%), 10 melanocytic lesions (21,95%), 2 lymphoid lesions (4.87%). From the 28 cases that had a preoperative clinical hypothesis only 17 presented a histopathological confirmation of the diagnosis (60.71%).</p> <p>Conclusion</p> <p>The most common caruncle lesions were epithelial tumors followed by chronic inflammation and melanocytic lesions. Although most of the lesions were benign, there was a great number of misdiagnose based on the clinical suspicious.</p

Malignancy in the blind painful eye - report of two cases and literature review

Background: Few cases of malignant tumors arising in a blind painful eye have previously been described. We described two cases of a blind painful eye containing an unsuspected tumor, which were enucleated to relieve the pain.Case presentations: Case 1: A 57 year-old Caucasian man presented with recurrent orbital cellulitis and endophthalmitis in the left eye (OS). the OS was blind and painful and an enucleation was performed showing a uveal melanoma by histopathological exam. Case 2: A 54 year-old Caucasian man with previous history of a rhegmatogenous retinal detachment in his left eye presented a blind painful eye. Enucleation was performed revealing a well-differentiated B-cell lymphoma of uveal tract with extra ocular extension.Conclusion: in the management of a blind painful eye, it is extremely important to rule out an intraocular malignancy particularly in those patients who have not been followed by an ophthalmologist.Universidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilMcGill Univ, Dept Ophthalmol, Henry C Witelson Ocular Pathol Lab, Montreal, PQ H3A 2T5, CanadaPathol & Cytopathol Lab, LAC, Campo Grande, MS, BrazilUniv Desenvolvimento Estado & Regiao Pantanal, Campo Grande, MS, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, São Paulo, BrazilWeb of Scienc

Blue-light filtering alters angiogenic signaling in human retinal pigmented epithelial cells culture model

Background: light exposure and more specifically the spectrum of blue light contribute to the oxidative stress in Age-related macular degeneration (AMD). The purpose of the study was to establish whether blue light filtering could modify proangiogenic signaling produced by retinal pigmented epithelial (RPE) cells under different conditions simulating risk factors for AMD. Methods: three experiments were carried out in order to expose ARPE-19 cells to white light for 48 h with and without blue light-blocking filters (BLF) in different conditions. In each experiment one group was exposed to light with no BLF protection, a second group was exposed to light with BLF protection, and a control group was not exposed to light. The ARPE-19 cells used in each experiment prior to light exposure were cultured for 24 h as follows: Experiment 1) Normoxia, Experiment 2) Hypoxia, and Experiment 3) Lutein supplemented media in normoxia. The media of all groups was harvested after light exposure for sandwich ELISA-based assays to quantify 10 pro-angiogenic cytokines. Results: a significant decrease in angiogenin secretion levels and a significant increase in bFGF were observed following light exposure, compared to dark conditions, in both normoxia and hypoxia conditions. With the addition of a blue light-blocking filter in normoxia, a significant increase in angiogenin levels was observed. Although statistical significance was not achieved, blue light filters reduce light-induced secretion of bFGF and VEGF to near normal levels. This trend is also observed when ARPE-19 cells are grown under hypoxic conditions and when pre-treated with lutein prior to exposure to experimental conditions. Conclusions: following light exposure, there is a decrease in angiogenin secretion by ARPE-19 cells, which was abrogated with a blue light - blocking filter. Our findings support the position that blue light filtering affects the secretion of angiogenic factors by retinal pigmented epithelial cells under normoxic, hypoxic, and lutein-pretreated conditions in a similar manner