Involvement of TLR9 in priming the immune response in oral papillomatosis induced by low-risk HPV.

Oral papillomatosis represents a benign lesion of the oral mucosa often induced by human papillomavirus (HPV) or having a non-infection local or general etiology. HPVs are very well adapted and efficient viruses able to produce changes in the immune system, endowed with the ability to replicate in the keratinocytes and to remain silent. The natural evolution of HPV infection is different, depending on the efficiency of the innate immune system. The purpose of this study was to explore Toll-like receptor 9 (TLR9) immunohistochemical expression in low-risk (LR)-HPV oral infection and its ability to facilitate an efficient immune response by activating the macrophages, which serve as main antigen-presenting cells. Samples of two groups of oral mucosae - LR-HPV-positive and HPV-negative - were processed for immunohistochemistry technique and incubated with antibody against TLR9 and cluster of differentiation 68 (CD68). Image analysis and morphometry were conducted to assess the intensity of TLR9 immune signal in the epithelium and the number of macrophages labeled by CD68. We found a statistically significant difference between macrophage count for the subjects in HPV-positive and HPV-negative groups; thought no significant differences of TLR9 immune signal was noted, which demonstrates a diminished immune response in HPV-positive group, probably influencing the time of lesion's clearance.

Fetal-maternal incompatibility in the Rh system. Rh isoimmunization associated with hereditary spherocytosis: case presentation and review of the literature.

Next to A and B antigens, agglutinogen D exhibits the highest immunogenicity. Following the transfusion of D-positive red blood cells (RBCs), almost 80% of D-negative recipients develop anti-D antibodies (Abs). Subsequently, anti-D immunization further promotes the synthesis of Abs towards other blood group antigens in or outside the Rh system. The D antigen is also involved in 95% of cases of hemolytic disease of the newborn. Transfusions, hemotherapy, grafts, and obstetric history (abortions, ectopic pregnancy, births) are all risk factors for Rh isoimmunization. In the case of ABO compatibility between mother and fetus, Rh-positive fetal RBCs that have reached the maternal bloodstream are not destroyed by group agglutinins, and Rh antigenic sites are not hidden by the maternal immune system. But a Rh-negative mother with a homozygous Rh-positive husband will certainly have a Rh-positive fetus. As it has an irreversible evolution, the Rh isoimmunization once installed cannot be influenced in the sense of decreasing the Ab titer, therefore, injectable globulin has no effect. A particular case was that of a newborn with Rh system incompatibility associated with hereditary spherocytosis The clinical balance at birth reflects the severe jaundice of the female newborn of 3140 g, gestational age 38∕39 weeks, extracted by lower-segment transverse Caesarean section, with a double loop nuchal cord, Apgar score 8. Because the jaundice was severe and atypical (face and upper chest), we considered the possibility of coexistence of hemolytic disease of the newborn by Rh blood group incompatibility associated with hereditary spherocytosis, as it turned out to be true and mentioned. Changes in genes encoding proteins in the structure of the RBC membrane have amplified hemolysis induced by maternal-fetal isoimmunization in the Rh system. Massive hemolysis accentuated by congenital spherocytosis, confirmed later, imposed blood transfusion and dynamic monitoring.

The Angiogenic Balance and Its Implications in Cancer and Cardiovascular Diseases: An Overview.

Angiogenesis is the process of developing new blood vessels from pre-existing ones. This review summarizes the main features of physiological and pathological angiogenesis and those of angiogenesis activation and inhibition. In healthy adults, angiogenesis is absent apart from its involvement in female reproductive functions and tissue regeneration. Angiogenesis is a complex process regulated by the action of specific activators and inhibitors. In certain diseases, modulating the angiogenic balance can be a therapeutic route, either by inhibiting angiogenesis (for example in the case of tumor angiogenesis), or by trying to activate the process of new blood vessels formation, which is the goal in case of cardiac or peripheral ischemia.

The Clinical Profile of Cat-Scratch Disease's Neuro-Ophthalmological Effects.

Cat-scratch disease is an illness caused by Bartonella henselae that occurs as a result of contact with an infected kitten or dog, such as a bite or scratch. It is more prevalent in children and young adults, as well as immunocompromised individuals. There are limited publications examining the features of CSD in patients. As such, the purpose of this research was to assess the clinical neuro-ophthalmological consequences of CSD reported in the literature. Among the ophthalmologic disorders caused by cat-scratch disease in humans, Parinaud oculoglandular syndrome, uveitis, vitritis, retinitis, retinochoroiditis and optic neuritis are the most prevalent. The neurological disorders caused by cat-scratch disease in humans include encephalopathy, transverse myelitis, radiculitis, and cerebellar ataxia. The current review addresses the neuro-ophthalmological clinical manifestations of cat-scratch disease, as described in papers published over the last four decades (1980-2022). All the data gathered were obtained from PubMed, Medline and Google Scholar. The current descriptive review summarizes the most-often-encountered clinical symptomatology in instances of cat-scratch disease with neurological and ocular invasion. Thus, the purpose of this review is to increase knowledge of cat-scratch disease's neuro-ophthalmological manifestations.

The procoagulant status. Hypercoagulability as a risk factor of primary and secondary infertility.

Thrombophilia is a disorder that makes patients susceptible to intravascular thrombosis that may increase the risk of developing a pregnancy on a known pathology. The female patient diagnosed with hypoplastic uterus and hereditary thrombophilia had a favorable evolution under properly administered anticoagulant treatment. The homozygous status for the C677T mutation may lead to an increase in plasma homocysteine levels, especially in pregnant women, being an associated risk factor for thrombosis. The risk of developing intravascular thrombosis requires primary prevention measures by adding D-dimers in the early diagnostic algorithm, being the most accurate marker of hypercoagulability and endogenous fibrinolysis. The corroboration of the hypercoagulability status with the results of genotyping, the frequencies of the minor/major alleles studied, single mononucleotide polymorphisms (SNPs) and the establishment of preventive therapy, aims to prevent intravascular thrombosis and thromboembolic phenomena.

Status thymicolymphaticus: real or fake?

Sudden infant death syndrome (SIDS) is the sudden, unexpected death of an infant less than one year of age that remains unexplained after a full investigation. SIDS is the most frequent cause of death of infants between two weeks and one year of age, explaining 35% to 55% of all deaths in this age group. We report a newborn male who died soon after birth. The newborn was cyanotic, bradycardic at first, and then asystolic; without any vesicular murmur, apneic, low amplitude thorax movements, even under conditions of positive pressure ventilation on the endotracheal tube. The microscopic aspect thymus highlighted a corticomedullary ratio quite high in favor of the cortical, rich in lymphocyte population, with the dilated subcapsular sinuses. In this report, we considered that cardiorespiratory failure, which was the immediate cause of death, could have been caused by the thymus hypertrophy. This hypertrophy can be a complication of an intrapartum preexistent condition, most probably of hepatic nature.

Synchronous gastric tumors - case presentation.

Synchronous gastric tumors, and, especially the presence of an adenocarcinoma and gastrointestinal stromal tumors, are less frequent. We present the case of a 75-year-old patient, with no gastrointestinal pathology in the medical history, who was admitted for marked asthenia, nausea, coffee grounds vomiting, inappetence, dizziness, weight loss and periodical epigastralgias. The clinical and imagistic examinations highlighted an ulcerative, infiltrative, bleeding tumor formation, present on the anterior side and subcardially on the small curvature. During the surgery, there was highlighted a second tumor, whitish, of about 2.5 cm, prominent under the peritoneal serous, of firm consistency and with an adherence to the stomach muscles. For removing the two tumors, there was performed total gastrectomy with esophagus-jejunal termino-lateral anastomosis, with jejunum ansa "in omega". The histopathological and immunohistochemical examinations established that the first tumor was a poorly differentiated carcinoma, and the second was a gastrointestinal stromal tumor. The patient's evolution was a good one, both clinically and biologically, the imagistic examinations performed after six and 12 months highlighting the lack of local relapses and absence of metastases.

Chondrosarcoma of the hyoid bone: a case report.

Chondrosarcoma is a malignancy of the mesenchymal tissue derived from transformed cells that produce the cartilage matrix. In the neck area, it represents less than 0.5% of malignant tumor pathology. Chondrosarcoma of the hyoid bone is extremely rare, only 20 cases having been published so far (PubMed 2014). We present the case of a 30-year-old patient from the urban area, admitted in the ENT (Ear, Nose & Throat) Emergency Service with inspiratory dyspnea, dysphagia, stomatolalia, with evolutive and progressive clinical history of 2-3 months. Endoscopic examination revealed a pharyngolaryngeal tumor process located in the right vallecula, who by mass effect displaces the above-hyoid epiglottis. CT (computerized tomography) scan described a cervical polycystic tumor aspect, with multiple septae and inside calcifications with a diameter of 3-4 mm. Surgery consisted in removal of the tumor process together with the hyoid bone. Histopathological and especially immunohistochemical examination established the diagnosis of low-grade chondrosarcoma of the hyoid bone. For assessment of the phenotype of the tumor cells, the following immunohistochemical markers were used: p53, Ki67. The patient followed radiochemotherapic oncological treatment and returned for regular follow-ups. There was a positive development with no signs of regional or remote relapse or metastasis for 24 months after surgical treatment. Surgery is the treatment of choice, with complete removal of the tumor, with chemoradiation playing an adjuvant role. Regular tracking of the patient is mandatory.

CT characters versus morphopathological characters in pharyngeal squamous cell carcinoma.

Pharyngeal squamous cell carcinoma is a rare neoplasm, whose incidence increases with age. Computed tomography (CT) imaging is an easy way to explore the pharyngeal region, having the advantage of being able to highlight and characterize the existence of a tumor in this region, and to determine its local extension and lymphatic metastasis. In this group were included a total of 27 patients, who, following the histopathological findings were diagnosed with pharyngeal squamous cell carcinoma and who have previously received a CT scan. CT examination protocol included a native scan and post-intravenous administration of contrast medium, in both the arterial phase and in parenchymal and venous phase. The scan was made with 2 mm thin sections, subsequently were performed coronal and sagittal reconstructions. The examination plan included the thoracic region down to the aperture. The paper tries to establish correlations between the morphological appearance and semiological computed tomography characters of the lesions.

Colorectal cancer - clinical and morphological aspects.

INTRODUCTION: Colorectal cancer (CRC) is one of the most common and most serious malignancies worldwide. Its incidence has increased by more than 200 000 in 2008, both in men and in women. Although CRC is a well-studied malignancy which has a slow progression, known risk factors and pre-neoplastic lesions that can be detected and treated, its incidence is on the rise. In our study, we clinically, histologically and immunohistochemically evaluated a group of 317 patients with colorectal cancer who underwent surgery. PATIENTS AND METHODS: The trial included 317 colorectal cancer patients hospitalized in the second Department of General Surgery within the Emergency County Hospital of Craiova, Romania, between January 2005 and December 2009, aged between 18 and 89 years. After undergoing clinical and laboratory work-up, all patients were submitted to surgery with curative intent. Resection specimens were collected and histological slides were produced from the biological material. Usual histological staining, Hematoxylin-Eosin and trichromic Goldner-Szekely, as well as immunohistochemistry with anti-Ki67, anti-caspase 3, anti-p53 and anti E-cadherin antibodies was also performed. RESULTS: Regarding gender distribution of cases in the study group was a slightly higher incidence in the number of women affected by neoplasia (n=166, 52.35%) than males (n=151, 47.65%). Analysis of incidence per decade of age showed highest figures between 61-70 years, but we also observed comparable values for the decade 51-60 years. Analysis of topography showed higher incidence of cancer of the rectum (119 cases, representing 37.53%) compared to individual segments of the colon. Average size determined for all locations was 5.05 cm, with a median located at 4.82 and a standard deviation of 1.99. Regarding the degree of cell differentiation, out of the total of 245 adenocarcinomas, a number of 87 (35.52%) were well-differentiated adenocarcinomas, 127 (51.83%) were moderately differentiated, and 31 (12.65%) cases were poorly differentiated adenocarcinomas. Index of cell proliferation, Ki67, had a moderate and intense reaction to all the cases studied. Very few tumor cells were immunohistochemically positive for caspase 3, regardless of the degree of tumor differentiation. E-cadherin was intense in well-differentiated adenocarcinomas. In our study, of 42 colon adenocarcinomas, 29 (69%) were highly positive to anti-p53 antibody, the remaining being negative. CONCLUSIONS: Colorectal cancer was diagnosed especially in people over 50 years. Analysis of topography showed higher incidence of cancer of the rectum compared to segments of the colon. More than half were presented in stages III and IV. The histopathological study showed that about 98% of colorectal neoplasms were adenocarcinomas, frequently with moderate differentiation.

Prognostic factors in anterior skull base meningiomas.

AIM: Histopathological and immunohistochemical study of prognostic factors in anterior skull base meningiomas in order to determine the post-operative management. MATERIALS AND METHODS: The studied material consisted in resection specimens from 65 patients with anterior skull base meningiomas hospitalized in Clinic of Neurosurgery, National Institute of Neurology and Neurovascular Diseases, Bucharest, Romania, and diagnosed in the Department of Pathology of the same Institute, between 2007 and 2013. The biological material was processed by standard histological technique with Hematoxylin and Eosin staining which allowed the classification of tumors according to WHO 2007 system and the assessment of the morphological parameters of known prognostic value. Subsequently, the tumor fragments were submitted to immunohistochemistry to evaluate the proliferative activity (Ki-67 labeling index) and progesterone hormone receptor (PR) status. RESULTS: 83.07% of the 65 anterior skull base meningiomas were WHO grade I tumors; the grade II tumors accounted 15.38%, while the grade III tumors were rare (1.53%). Mitotic activity was variable, reaching up to 14 mitoses/10 HPF (high-power field) in atypical and anaplastic tumors; mitoses were absent in 64.81% of grade I tumors; the average mitotic index in grade II tumors was 5.15 mitoses/10 HPF. Both mitotic activity and infiltrative and invasive tumor growth (the latter found in 36.92% of cases) were correlated with tumor grade. Ki-67 labeling index ranged between 1.1% and 7.7%, with the highest value found in anaplastic tumor; progesterone receptors (PR) were expressed with variable index in 84.61% of cases. The immunonegative PR tumors were represented by 16.66% of grade I tumors and by the only grade III tumor. In contrast to PR, Ki-67 expression was statistically correlated with tumor grade. The comparison between the expression of Ki-67 and PR revealed an inverse relationship between the level of PR expression and the proliferative activity intensity. CONCLUSIONS: We found that PR expression decreases as the biological behavior of tumor becomes more aggressive; it may be related with an increased risk of recurrence, making the postoperative surveillance more rigorous in these patients.

Matrix metalloproteinase -7, -8, -9 and -13 in gingival tissue of patients with type 1 diabetes and periodontitis.

There is scientific data to support the existence of a two-way relationship between diabetes and periodontitis, with diabetes increasing the risk for periodontitis, and periodontal inflammation negatively affecting the diabetic status. Our study aims to investigate the expression of MMP-7, -8, -9 and -13 in the gingiva of the young patients with aggressive periodontitis (AP) and type 1 diabetes mellitus (T1D). Gingival biopsies were harvested from five adult patients aged 19-29 years with T1D+AP with moderate (three cases) to severe (two cases) forms of AP and from four adult patients aged 18-28 years with moderate AP without T1D. The MMP-7 immunoreaction was positive in the five cases with T1D+AP with different staining patterns. The MMP-8 immunostaining was positive in all cases. The reaction was more intense in cases with T1D+AP, especially in those with severe periodontitis. The MMP-9 immunoreaction was present in all the structures of the gingival mucosa with different intensity, being frequently present surrounding the blood vessels of the chorion. In most of the patients, reaction to MMP-9 was intense, localized at the level of the cells in the superficial chorion and very rarely at the level of some dispersed cells in the connective vascular islands. MMP-13 was present in all cases, but it was more intense in the two cases with T1D+AP with probing depth (PD)>6 mm when it had similar patterns as MMP-9 staining and in one case with AP when the staining was observed strictly in the lamina propria associated with moderate chronic inflammatory infiltrate. The expression of MMP-7, -8, -9 and -13 in the gingiva of the young patients with aggressive periodontitis and T1D was positive in all studied cases supporting the hypothesis that both are inflammatory diseases with common pathogenic mechanisms involving inflammatory mediators and may be possible biomarkers of disease status.

Gastric eosinophilia--clinical and morphological correlations.

Eosinophils of the gastrointestinal tract are involved in the host immune response that occurs in the presence of the pathogens in the digestive lumen, taking part in maintaining the homeostasis of the gastrointestinal epithelium. Their involvement in inflammatory processes of chronic gastritis is less known. In our study, we identified the presence of eosinophils in chorion gastric mucosa (lamina propria) in over 34% of chronic gastritis. Eosinophils were more numerous in atrophic gastritis with intestinal metaplasia. More than 65% of chronic gastritis associated with Helicobacter pylori also had eosinophils in the gastric mucosa.

Cerebral microvascular changes induced by rich cholesterol and saturated fatty acid diet in Wistar rats.

UNLABELLED: The impact of an excess of fatty acids in the diet on cardiovascular diseases has been studied and discussed both in human and animal studies. Generally, excessive saturated fats increase the risk, while unsaturated fats are considered less harmful. Our aim was to perform an experimental study in order to analyze how fatty diet quality (unsaturated vs. saturated fatty acids) influences atherogenesis. MATERIALS AND METHODS: In our experimental study, 18 adult Wistar rats were randomly divided into two equal groups. One group was subjected to a rich unsaturated fatty acid diet (untar) and the other group to a rich saturated one (palm oil). Three animals from each group were sacrificed after 12, 18, and 48 weeks. The brain was removed and microscopically examined after Hematoxylin-Eosin, Orcein and Masson's trichrome classical staining, and after immunohistochemical marking using the anti-alpha smooth muscle actin antibody. RESULTS: Rats sacrificed after 12 weeks revealed modicum lesions, as intimal vacuoles or minute intraluminal thrombosis, and cerebral parenchymal edema. After 18 weeks, some of rats subjected to a rich saturated fatty acid diet presented vacuoles found in all arteriolar wall layers, and a tendency towards parietal thrombosis. In rats subjected to a rich unsaturated fatty acid diet, the subintimal arteriolar vacuolization was associated with an intramural and adventitial fibrosis. In rats sacrificed after 48 weeks, lesional polymorphism was pronounced, but in rats subjected to a rich unsaturated fatty acid diet complete luminal thrombosis was followed by a an organized thrombus with multiple capillary channels. Although in Wistar rats atherosclerosis appeared only after intensive changes in diet, different experimental studies showed that, in transgenic rats, rich saturated fatty acid diet induced progressive atherosclerotic lesions, resembling those observed by us, but also some aspects described in human pathology. CONCLUSIONS: Our experimental study reveals differences in atherogenesis under saturated vs. unsaturated fatty diet.

Bony metaplasia in a caecum adenocarcinoma.

Ectopic bone formation in the digestive tract is a very rare phenomenon in pathology. Most cases of bone metaplasia were found in distal colon tumors, rectum and sigmoid respectively. We present a case of well-differentiated adenocarcinoma of the caecum (the second case of literature) associated with bone metaplasia, which debuted atypical, with symptoms of infectious enterocolitis, in a 72-year-old female patient, with no history of digestive pathology. Highlighting bone metaplasia was achieved by current histological techniques. Patient's evolution was favorable with surgical treatment and chemotherapy.

The importance of immunohistochemical evaluation of the vascular changes from the decidua and placenta in recurrent pregnancy loss.

The angiogenesis is a complex process, incompletely understood, regulated by various stimulating and inhibiting angiogenic factors. In the present study, we proposed to evaluate the angiogenic changes that occur in the cases with recurrent pregnancy loss comparing with a control group represented by women with requested abortion. The evaluation of the changes in the vascular bed was made by immunohistochemical methods, evaluating the answer of the curettage products to the mouse anti-human CD31 and CD34 monoclonal antibodies immunolabeling. The endothelial cells reaction to the CD31 antibody was different, very intense in the normal or slightly congestive vessels. The endothelial cells from the strongly congestive vessels had a light and scratchy reaction. We found intense positive reactions in the control group for CD34 in the vessels from the villous axis and also in the vessels from the spongious decidua. In the study group, we found light positive reaction in the vessels from the decidua situated in the proximity of the necrotic areas; we found a light positive reaction also in the vessels and mesenchymal fibroblasts from some chorial villous axis.

Histological and immunohistochemical aspects of cerebral vessels of the elderly.

The central nervous system is considered the most complex morphological structure of the human body. Between nervous tissue and cerebral circulation is a very close relationship, so transient vascular meningocerebral disturbances cause changes in neuronal function clinically expressed as various neurological signs and symptoms, especially in the elderly. In this study, we examined from the histological and immunohistochemical point of view encephalon fragments collected from 24 patients aged between 46 and 85 years. All patients exhibited changes in meningocerebral vessels, ranging from atheromatous plaques to vascular rupture. Immunohistochemical techniques have shown changes in the vascular endothelium, smooth muscle fibers of arterial walls and blood-brain barrier disruption.

Histopathological and immunohistochemical aspects in chronic suppurative maxillary rhinosinusitis.

Chronic rhinosinusitis is a multifactorial disease with pathophysiological mechanisms, which remain unclear, and with a high prevalence worldwide. They generate social problems due to the high number of days of leave and relatively elevated medical expenses. The histopathological and immunohistochemical study that we conducted revealed many lesional aspects of the epithelium of the sinus mucosa, which ranged from hypertrophy, hyperplasia and metaplasia, to erosion and discontinuities. In the chorion of the sinus mucosa there was an inflammatory infiltrate composed mainly of lymphocytes, plasma cells and macrophages, and also a highly developed vascular network. Among immune cells, T-cells appeared to be more numerous than B-lymphocytes and macrophages. We believe that microscopic changes are due mainly to microscopic organisms that make up the biofilm of the sinus cavity, whose virulence has been more or less influenced by exogenous or endogenous factors.

The importance of tumor proliferation markers in assessing lesions of the palatine tonsil.

Oropharyngeal cancer, and especially squamous cell carcinoma, is one of the most common cancers worldwide, and its incidence is increasing, with the palatine tonsil being one of the main locations. The etiopathogenic factors, together with its location as well as the available immunohistochemical methods, make this type of cancer an accessible one in terms of diagnosis. However, it is usually diagnosed in late stages. Therefore, we tried to elucidate the causes of treatment failures and development of local recurrence. For this, we reassessed the proliferative pattern of tonsil lesions using the anti-p53, anti-PCNA and anti-Ki67 antibodies on 73 tonsil fragments collected after curative surgery on adults aged between 28 and 86 years. Following the reevaluation of the histopathological examination using markers for cell proliferation, the diagnosis was modified in 16 cases, representing about 22% of the cases take into study. By using immunohistochemical markers in the histopathological examination the diagnosis is improved, leading to a more appropriate therapeutical approach.

Pterygium: histological and immunohistochemical aspects.

INTRODUCTION: Pterygium represents a triangular conjunctivo-epithelial overgrowth, proliferating from the bulbar conjunctiva and covering the cornea, causing severe vision loss. It is an abnormal growth and differentiation of the conjunctive epithelial structures of the corneal limbus. Chronic exposures to solar ultraviolet radiation, heat and dust, as well as viral agents, are the most common pathogenic entities involved in its evolution. Recent studies linked pterygium with neoplastic proliferation, as ocular limbic stem cells and p53-protein expression are altered. MATERIALS AND METHODS: Our study was conducted on 84 fragments of pterygium, collected after surgery from patients admitted between 2008 and 2009 in the Departments of Ophthalmology of the Emergency County Hospital of Craiova and Hospital of Rovinari. Histological studies were performed by staining with Hematoxylin-Eosin, light green trichromic (Goldner-Szekely technique) and PAS-Hematoxylin. Immunohistochemistry highlighted the T-lymphocytes by using the CD3 antibody, B-lymphocytes by using the CD20 antibody and cells of the macrophage system using the CD68 antibody. The slides were analyzed under a 55I Nikon microscope, resulting pictures being captured with a 5 MP digital camera and digitally retrieved and enhanced using the dedicated NIS-Elements software. RESULTS: Histology showed the presence of a conjunctivo-epithelial structure, significantly different from the structure from which it developed. In 20% of the cases, the covering epithelium was similar to that of the bulbar conjunctival mucosa. In some cases, when pathogens were more active in the environment, the appearance of the covering epithelium of the membrane appeared pleomorphic, with dysplastic aspects, suggesting significant alteration of cell proliferation and differentiation. In approximately 75% of patients, we identified goblet cells in the surface epithelium. They appeared either isolated or associated in variable numbers, structures resembling intraepithelial glands. These particular cells synthesize and accumulate PAS-positive mucines rich in glycosaminoglycans, and are usually found in conjunctival epithelium. We observed a number of invaginations in the connective tissue underlying the epithelium, mostly formed by goblet cells, this giving the aspect of mucous glands, similar to the "glands of Henle". A highly developed vascular neoformation network, consisting of arterioles, venules and a very large number of capillaries can also be found in the connective tissue. Immunohistochemistry suggested that B-lymphocytes marginally take part in the immune response in pterygium. T-lymphocytes formed the majority of the mass of immune system cell present in connective tissue of the pterygium. Macrophage-type cells were distributed unevenly in the pterygium tissue, as the intensity of the inflammatory process varies depending on antigen levels. CONCLUSIONS: Pterygium shows significant changes both in the epithelium and in the underlying connective tissue. Immune cell infiltrate was diffuse, more abundant in areas with erosion of the covering epithelium.