Immunophenotypic profiles in chalazion and pyogenic granuloma associated with chalazion

PURPOSE

To evaluate immunophenotypic profiles of infiltrating cells in surgically excised tissues of chalazion and pyogenic granuloma associated with chalazion.

METHODS

Eighty-two surgical specimens from 74 consecutive patients newly diagnosed with chalazion or chalazion-associated pyogenic granuloma at Tokyo Medical University Hospital between 2016 and 2022 were studied. Sixty specimens were chalazion lesions and 22 specimens were pyogenic granuloma lesions (from 15 men and 7 women, mean age 36.6 ± 14.4 years). All patients were immunocompetent Asian Japanese adults. Specimens were analyzed by immunohistochemistry and flow cytometry. Flow cytometry was performed using the following antibodies: CD3, CD4, CD8, CD11b, CD11c, CD16, CD19, CD20, CD23, CD25, CD34, CD44, CD56, CD69, and CD138.

RESULTS

In flow cytometric analysis, the proportion of cells expressing the T cell marker CD3 was significantly higher compared with other immune cells expressing specific markers (p < 0.0001), and the proportion of CD4-positive T cells was significantly higher than that of CD8-positive T cells (p < 0.0001), in both chalazion and pyogenic granuloma specimens. The chalazion and pyogenic granuloma lesions shared similar immunophenotypic profile characterized by predominant T cell infiltration, and CD4 T cells dominating over CD8 cells. The pattern of expression of CD4 and CD8 in the specimens was confirmed by immunohistochemistry.

CONCLUSION

The present study demonstrates immunophenotypic features of chalazion and chalazion-associated pyogenic granuloma. Although various inflammatory cells are involved in the pathology of chalazion and pyogenic granuloma, a significantly higher proportion of CD4-positive T cells may be closely related to the pathological mechanisms of both lesions.

The Correlation between VEGF and CD34 Protein Marker and Pyogenic Granuloma

BACKGROUND

A typical non-neoplastic connective tissue proliferations called a pyogenic granuloma. A vascular adhesion molecule used to assess angiogenesis is the CD34 marker. The primary memberof a family of growth factors, VEGF helps in generating and maintaining the lymphatic and blood circulation systems.

OBJECTIVE

The aim of the study was to know the correlation between VEGF and CD34 protein marker and pyogenic granuloma.

METHODS

Thirty-one formalin fixed paraffin embedded (FFPE) blocks were taken from female pyogenic granuloma patients ranging in age from 29 to 70. The IHC was used to identify VEGF and CD34 expression in the cytoplasm of the cells.

RESULTS

Seventeenout of 31 patients had VEGF positive expression. Twenty-sixout of 31 had CD34 positive expression and 5 with no expression (negative expression). Brown-stained cytoplasm showed high VEGF and CD34 expression, whereas blue stained cytoplasm showed no VEGF and CD34 expression in these cells.

CONCLUSIONS

The results suggest the role of suchbiomarkers in the oral pyogenic granuloma pathogenesis, and it appears that CD34 and VEGF are valuable biomarkers in evaluating vascular and inflammatory diseases like pyogenic granuloma.

Development of pyogenic granuloma with strong vascular endothelial growth factor receptor-2 expression during ramucirumab treatment

The angiogenesis inhibitor ramucirumab (IMC-1121B) is a fully humanised IgG1 monoclonal antibody targeting the extracellular domain of vascular endothelial growth factor receptor 2. Ramucirumab has been approved as a second-line treatment for lung cancer. Pyogenic granuloma is an acquired, benign vascular tumour of the skin or mucous membrane. We encountered a patient with pyogenic granuloma who was treated with ramucirumab. The patient was a 48-year-old Japanese woman with advanced lung cancer who had been heavily pretreated using several lines of chemotherapy. Ramucirumab was administered as the fifth-line treatment with docetaxel. After 10 days, a painless rice-coloured or pink papule appeared on her finger. One month later, it increased in size to 20 mm. We examined the pathological condition by immunostaining using the resected specimen diagnosed as pyogenic granuloma. Paradoxically, this vascular tumour arose during the administration of an angiogenesis inhibitor.

Mast cells and its relation to collagen and VEGF in oral inflammatory lesions

BACKGROUND

The aim of this study was to evaluate the population of intact and degranulated MCs in oral inflammatory lesions.

METHODS

A cross sectional study of 48 samples, including inflammatory fibrous hyperplasia, pyogenic granulomas, periapical granulomas and radicular cysts, was performed. Samples of normal gingival mucosa were used as controls. The degree of edema and lymphoplasmacytic infiltrate was determined by the analysis of hematoxylin-eosin (HE)-stained sections. To determine the collagen fibers contents and correlate it with the MC count, sections stained with Sirius red and Toluidine blue were used. Immunohistochemistry with an antivascular endothelial growth factor (VEGF) was also used to count endothelial cells.

RESULTS

Although the total number of intact MCs was higher in the oral inflammatory lesions, these differences were not statistically significant (P=0.33). There were statistically significant differences between the numbers of degranulated MCs from the lesions and those from the normal oral mucosae (P=0.001) and a positive correlation between the number of MCs and the degree of inflammation (P<0.001). The MC count did not correlate with the collagen fibers or VEGF positive cells (P>0.05).

CONCLUSIONS

The involvement of MCs in the pathogenesis of the oral inflammatory lesions is suggested. However, there was no positive correlation with these cells and collagen fibers or angiogenesis in the lesions studied.

A Critical Analysis of Eleven Periocular Lobular Capillary Hemangiomas in Adults

PURPOSE

To provide a critical analysis of a series of periocular lobular capillary hemangiomas in adults, outlining characteristic clinical and histopathologic patterns in comparison with those of other vascular tumors of adults and children.

DESIGN

Retrospective observational case series.

METHODS

Review of clinical data, hematoxylin-eosin-stained sections, and immunohistochemical studies of smooth muscle actin (SMA), D2-40, CD34, and glucose transporter 1 (GLUT-1).

RESULTS

The 7 female and 4 male patients were diagnosed with periocular lobular capillary hemangioma at a median age of 39 years (range, 17-82 years). The tumors were small (3-14 mm, median size 6 mm) and well circumscribed, arose over the course of weeks to months, and developed most commonly in the canthal region, followed by the upper eyelid skin. The tumors were all composed microscopically of repeating units of various sizes (lobules) consisting of CD34-postive, GLUT-1-negative endothelial cells and SMA-positive pericytes arranged in macro- or microlobules. Some foci also exhibited ectatic vessels or diffuse, nonlobular capillary proliferations. Excision was curative without recurrence.

CONCLUSION

Although capillary hemangiomas are more common in children, lobular capillary hemangiomas can also arise in the periocular region of adults. Some histopathologic features of these lesions are shared with those of infantile hemangioma and tufted angioma of children, but features of the clinical presentation and the results of immunohistochemical staining patterns are distinctive.

Diagnostic utility of WT-1 cytoplasmic stain in variety of vascular lesions

Vascular lesions are commonly encountered in routine pathologic practice and often pose diagnostic challenges owing to their morphologic diversity. Although WT-1 expression was reported in some vascular tumors, little is known about its staining patterns in a spectrum of vascular lesions from various locations. We examined WT-1 immunostain in 95 cases of vascular lesions including angiosarcomas (AS, 19 cases), hemangioendotheliomas (HE, 5), Kaposi's sarcomas (KS, 4), cavernous hemangiomas (CVH, 12), capillary hemangiomas (CPH, 7), pyogenic granulomas (PG, 4), lymphangiomas (LA, 4), hemangiopericytomas (HP, 5), glomus tumors (GT, 8), vascular malformation (VM, 13) and granulation tissue (GRT, 14). Strong WT-1 cytoplasmic stain was invariably observed in all cases of malignant and borderline vascular tumors including AS (19/19), KS (4/4) and HE (5/5). WT-1 was also consistently expressed in CPH (7/7), PG (4/4), and GRT (14/14), while it became weaker in VM (10/13) and often negative in CVH (2/12) and LA (0/4). WT1 stain was not demonstrated in HP (0/5) and rarely in GT (2/8). We conclude that consistent and diffuse WT-1 cytoplasmic stain in AS, HE and KS can be useful in distinguishing these tumors from poorly differentiated tumors with mimicking features. On the other hand, reliable WT-1 stain in CPH, PG and GRT may help in differential diagnosis with non-endothelial vascular tumors such as GT and HP. Recognizing the WT-1 cytoplasmic stain in a broad spectrum of benign and neoplastic tissues is critical in formulating appropriate immunohistochemical panels and avoiding misinterpretation of results.

Association study between clinicopathological variables and periodontal breakdown in gingival pyogenic granuloma

OBJECTIVE

The aim was to investigate a possible association between the immunoexpression of interleukin (IL)-4 and clinicopathological parameters with the periodontal breakdown observed in gingival pyogenic granuloma (PG).

MATERIALS AND METHODS

Paraffin-embedded samples of gingival PG (n = 46) were prepared for histological and immunohistochemical assessment. Demographic and clinical parameters were assessed by criteria based on age stratum, gender, smoking habit, evolution course, location, lesion size, macroscopic appearance, predisposing factors, recurrence, and periodontal breakdown. Histological assessment included the appearance of epithelial lining, microvessel density, inflammatory infiltrate density, interstitial fibrosis, and histological arrangement. A staining intensity distribution (SID) score was used to assess IL-4 immunoreactivity. The association between candidate predictor variables and periodontal breakdown was analyzed individually and adjusted for confounding using a bivariate binary logistic regression model.

RESULTS

Mean IL-4 SID values were significantly increased for long-standing and large lesions, presence of periodontal breakdown, high microvessel density, and moderate-to-severe inflammatory infiltrate density. While bivariate and univariate analyses revealed a positive association of the evolution course ≥12 months, lesion size >1 cm, high microvessel density, moderate-to-severe inflammatory infiltrate density, and IL-4 SID score ≥8.04 with periodontal breakdown, after bivariate logistic regression analysis, only the evolution course ≥12 months, moderate-to-severe inflammatory infiltrate density, and IL-4 SID score ≥8.04 remained as robust predictors of periodontal damage. Confounding and interaction effects between candidate predictor variables were also noted.

CONCLUSION

These findings suggest that while evolution course, inflammatory infiltrate density, and the overexpression of IL-4 may act as predictors of periodontal breakdown in gingival PG, there are mutual confounding and synergistic biological interactive effects with respect to the lesion size and microvessel density in the susceptible host that may be also associated with the bone resorption and tissue destruction.

CLINICAL RELEVANCE

Although the first-line therapy of gingival PG continues to be the surgical excision, this approach poses unwanted complications such as severe mucogingival defects and recurrence. Hence, early diagnosis and detection of these three significant predictor variables as well as timely surgical excision might help prevent the periodontal tissue destruction observed in some of these lesions.

Pyogenic granuloma of the sigmoid colon

Pyogenic granuloma (PG) is a polypoid form of lobular capillary hemangioma that usually occurs in the skin and some mucosal surfaces. However, it is extremely rare in the intestinal tract and its preoperative diagnosis is difficult. We report on a case of PG of the sigmoid colon in a 62-year-old woman with a 6-month history of rectal bleeding. A pedunculated polypoid lesion was detected by colonoscopy and a polypectomy was performed. A microscopical study revealed a lobular arrangement proliferation of varying sizes of capillaries within an edematous stroma. A critical review of the English literature yielded only another well-documented case of PG in the large intestine. Diagnostic consideration includes inflammatory polyp and other vascular tumors such as bacillary angiomatosis and the angiomatous variant of Kaposi's sarcoma. Precise recognition of this distinctive vascular neoplasm in the gastrointestinal tract is essential to avoid misdiagnosis and inappropriate treatment.

Pyogenic granuloma of the oral cavity: Comparative study of its clinicopathological and immunohistochemical features

There are two histological types of pyogenic granuloma (PG) of the oral cavity: the lobular capillary hemangioma (LCH) and non-LCH type. The aim of the present study was to examine and compare the clinical features, etiological factors, diameter of vascular elements and immunohistochemical features of LCH and non-LCH histological types of PG to determine whether they are two distinct entities. Thirty cases of LCH and 26 cases of non-LCH PG were retrieved and retrospectively studied. Clinically, LCH PG occurred more frequently (66.4%) as sessile lesion whereas non-LCH PG occurred as pedunculated (77%). Non-LCH PG was associated more frequently (86.4%) with etiological factors. The lobular area of the LCH PG contained a greater number of blood vessels with small luminal diameter than did the central area of non-LCH PG. In the central area of non-LCH PG a significantly greater number of vessels with perivascular mesenchymal cells non-reactive for alpha-smooth muscle actin and muscle-specific actin was present than in the lobular area of LCH PG. The differences found in the present study suggest that the two histological types of PG represent distinct entities.

Capillary hemangioma of the central nervous system: a comparative study with lobular capillary hemangioma of the skin

Capillary hemangiomas have rarely been reported to develop in the brain or spinal cord. Here we report the histological and immunohistochemical features of ten cases of central nervous system capillary hemangiomas (CNSCH) and compare these to those of lobular capillary hemangioma (LCH) of the skin. CNSCH showed a lobular architecture with lobules that were separated by fibrous tissue septa in six cases. The lobules were composed of numerous, tightly packed, capillary-sized vessels. A highly cellular area was seen in six cases. A blood-filled cavernous space and fibroendothelial papillae that mimicked papillary endothelial hyperplasia were seen in four cases. Stromal edema was observed in nine cases. These features were not statistically different from those of LCH of the skin, although the highly cellular area was more prominent and more frequent in cases of CNSCH. Immunohistochemical studies demonstrated no positive staining of endothelial cells within either lesion for erythrocyte-type glucose transporter protein, which is a selective marker for capillary hemangioma of infancy. Vascular endothelial growth factor immunostaining demonstrated positive cells in the solid or immature-appearing areas without vessel lumen formation in both lesions. Some of the endothelial cells and stromal cells were positive for glucocorticoid receptor immunostaining. The MIB-1 index of CNSCH was variable (mean 5.6%) and the apoptotic index of CNSCH was significantly lower than that of LCH of the skin. CNSCH are benign lesions with histological and immunohistochemical features similar to those of LCH of the skin.

Evaluation of anti-thrombomodulin antibody as a tumor marker for vascular neoplasms

BACKGROUND

Various endothelial markers are available for the evaluation of vascular tumors and malformations, including anti CD34, anti-CD31, von Willebrand factor (vWF), and anti-thrombomodulin (anti-TM) antibodies. All have their limitations, and we sought to compare the utility of anti-TM antibody as a marker for several types of vascular neoplasms vs. previously established endothelial markers.

METHODS

We examined immunostaining profiles of 30 capillary hemangiomas, 10 pyogenic granulomas, five tufted angiomas, 17 Kaposi's sarcomas, and nine angiosarcomas. Immunostains for TM, CD34, and vWF were carried out using a labeled streptavidin-biotin peroxidase detection system.

RESULTS

Anti-TM antibody showed moderately intense immunostaining in 89% of benign and malignant vascular neoplasms. Anti-CD34 antibody showed moderate to diffuse immunostaining in 98% of vascular neoplasms, and vWF showed weak focal staining in 84% of all vascular neoplasms examined.

CONCLUSION

Anti-TM antibody proved to be a sensitive marker for both benign and malignant vascular neoplasms. While not as sensitive as anti-CD34, it may have some advantages in specificity that would make it a more reliable vascular tumor marker in certain situations.

The roles of vascular endothelial growth factor and angiopoietin-2 in the regression of pregnancy pyogenic granuloma

OBJECTIVES

The molecular mechanism for the regression of pregnancy pyogenic granuloma after parturition remains unclear. It has been proposed that, in the absence of vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) causes blood vessels to regress. Therefore, we investigated the roles of Ang-2 and VEGF in the regression of pregnancy pyogenic granuloma.

MATERIALS AND METHODS

The effects of tumor necrosis factor-alpha (TNF-alpha) on the transcription of Ang-2 were tested in endothelial cells by reverse transcriptase-polymerase chain reaction. A total of 15 specimens, including granulomas taken from five gravidas during pregnancy, five after parturition, and five from normal gingiva were compared by immunoblot assays for their relative expressions of Ang-1, Ang-2, Tie-2, VEGF, and beta-actin. Double staining, immunohistochemistry for Ang-2, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling for apoptotic cells, were used to evaluate their regression. Finally, a fibrin gel culture system was used to investigate whether the withdrawal of VEGF and addition of Ang-2 could cause newly grown microvessels to regress.

RESULTS

TNF-alpha upregulated the expression of Ang-2 in all endothelial cell types tested. The protein levels of Ang-2 and Tie-2 were highest in the granulomas in pregnancy, followed by those after parturition and normal gingiva, while Ang-1 and beta-actin exhibited no significant differences. The amount of VEGF was high in the granulomas in pregnancy and almost undetectable after parturition. Double staining on granulomas after parturition revealed more apoptotic cells and less Ang-2 than did those in pregnancy. In the fibrin gel assay, VEGF alone or in combination with Ang-2 could protect microvessels from apoptosis, while Ang-2 alone had no effect.

CONCLUSIONS

Our findings suggest that a lack of VEGF is associated with apoptosis of endothelial cells and regression of granuloma. The roles of Ang-2 require additional study.

Benign vascular proliferations--an immunohistochemical and comparative study

Hemangiomas constitute a heterogeneous group of benign vascular proliferations. Their pathogenesis is not completely understood. In this study the expression of GLUT-1, VEGF, Ki-67, bcl-2 and apoptotic index in twenty-six cases of infantile capillary hemangioma (ICH), fifteen of lobular capillary hemangioma (LCH) and nine of epithelioid hemangioma were examined. The expression of GLUT-1 was confined to ICH group and was completely absent in LCH and EH. The significant differences in the expression of VEGF, proliferative index and apoptosis between ICH, LCH, EH were found. The proliferative index and VEGF expression were highest in LCH. Apoptotic index was similar in LCH an ICH but negative in EH. The lesions examined did not differ significantly in bcl-2 expression. The GLUT-1 expression was not only Ki-67 but also apoptosis independent. Our findings might reflect the differences in biology and pathogenesis of hemangiomas.

Lobular capillary hemangioma of the oral mucosa: clinicopathological study of 43 cases with a special reference to immunohistochemical characterization of the vascular elements

Clinical and histopathological features were investigated in 43 cases of oral lobular capillary hemangiomas (LCH) with a special reference to characteristics of the vascular elements. The lesions affected females more than males by a ratio of 1:1.5. Average age of the patients was 52.7 years. The lesions involved the gingiva (n = 15), the tongue (n = 13), the labial mucosa (n = 10) and other sites. The lesions appeared usually as a pedunculated mass with ulceration; size of the lesions was up to 15 mm. Histologically, a lobular area and an ulcerative area were distinguished. The density of vessels was about 1045/mm2 and 160/mm2 in the lobular and ulcerative areas, respectively. The average diameter of the vascular lumen was 9.1 5.6 mm (range: 2.8-42.0 mm) and 18.8 20.9 mm (range: 5.6-139.7 mm) in the lobular and ulcerative areas, respectively. In the lobular area, most of the vessels had an inner layer of endothelial cells showing positive reaction for von Willebrand factor (vWF) and CD34, as well as an outer layer of mesenchymal cells showing positive reaction for alpha-smooth muscle actin (ASMA). However, in the ulcerative area, there was a variety of types of vessels consisting of various proportions of both endothelial and ASMA-positive perivascular mesenchymal cells. These results indicate that most of the vascular elements in the lobular area resemble more pericapillary microvascular segments than they do capillaries. Thus, the authors propose the term 'lobular pericapillary hemangioma' to represent this type of lesion.

Pathogenetic roles of angiogenic factors in pyogenic granulomas in pregnancy are modulated by female sex hormones

BACKGROUND

An abundance of microvessels is the major phenotype of pyogenic granuloma, which has been considered a hormone-related lesion based on clinical observations. Although angiogenic factors and inflammatory cytokines have been implied to play roles in the pathogenesis of pyogenic granuloma, their links to female steroid hormones still remain to be elucidated. Since apoptosis is important in limiting inflammation, we also investigated whether steroid hormones could protect granuloma cells from apoptosis and, therefore, lead to overreactive inflammatory response.

METHODS

We employed immunoassays in a series of experiments, including human pyogenic granuloma in pregnancy, mouse air pouch granuloma and U937 (monoblastoid) cells in culture to clarify the relationship among vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta and female steroid hormones in granuloma formation. The apoptotic rates were analyzed in vivo and in vitro by terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end labeling (TUNEL) and flow cytometry, respectively.

RESULTS

Both in human and animal studies, the immunoassays (enzyme-linked immunoabsorbent assay [ELISA] and immunohistochemistry) detected significantly more VEGF and bFGF and less TNF-alpha in hormones than the control group, while TUNEL assay revealed less apoptotic cells in groups with pregnancy levels of hormones. In vitro, progesterone enhanced the expression of VEGF in LPS-treated U937 cells. Both estrogen and progesterone inhibited the apoptosis of U937 cells triggered by exogenous TNF-a

CONCLUSIONS

Female steroid hormones may have dual effects on the pathogenesis of pyogenic granuloma in pregnancy. The hormones not only enhance the expression of angiogenic factors in inflamed tissue, but also decrease apoptosis of granuloma cells to extend angiogenic effect.

Laryngeal pyogenic granulomas do not express oestrogen or progesterone receptors

The objective of this study was to determine the presence of oestrogen and/or progesterone receptors in laryngeal pyogenic granulomas and the impact of these receptors on recurrence of pyogenic granulomas. Twenty-two consecutive patients who underwent microlaryngoscopy and removal of pyogenic granulomas were studied retrospectively. The indications for surgery were airway compromise, failure of medical therapy and suspicion of malignancy. Twelve of these patients' granulomas were analysed for oestrogen and progesterone receptors. Charts were analysed for age, sex, location of the lesion, history of trauma, intubation or gastroesophageal reflux disease (GORD), airway symptoms and recurrence. Oestrogen/progesterone receptors were analysed following deparaffinization of specimens and immunostaining with prediluted anti-oestrogen receptor monoclonal antibody and anti-progesterone receptor monoclonal antibody. No sample expressed oestrogen or progesterone receptors. There were too few recurrences to detect if lack of these receptors played any role in determining outcome in this group. Most of the patients had a history of GORD, intubation or laryngeal surgery. There were 12 recurrences in four patients. All of the recurrences improved on prolonged courses of omeprazole. Pyogenic granulomas do not possess oestrogen or progesterone receptors and are unlikely to respond to hormonal therapy. Patients who have, or are being operated on for, laryngeal pyogenic granulomas should be placed on proton pump inhibitors to decrease the likelihood of recurrence.

Pyogenic granuloma following oculoplastic procedures: an imbalance in angiogenesis regulation?

BACKGROUND

Pyogenic granuloma is a vasoproliferative inflammatory response composed of granulation tissue. The pathogenesis is not entirely clear. We describe a series of patients with pyogenic granulomas occurring following common oculoplastic procedures and propose a common etiology.

METHODS

Sixteen cases of pyogenic granuloma that occurred after various oculoplastic procedures from 1991 to 2000 were collected from the files of two oculoplastic surgeons.

RESULTS

Pyogenic granulomas were found to occur at surgical and nonsurgical sites associated with tissue irritation or inflammation or both.

INTERPRETATION

Capillaries are a predominant component of wound healing and pyogenic granulomas. The growth and development of new capillaries follows an orderly sequence of events that is highly regulated by a variety of angiogenic factors. We postulate an imbalance in angiogenesis regulation as the common pathway for pyogenic granuloma development.

Syndecan-1 expression in different soft tissue tumours

BACKGROUND

In vitro studies have suggested that expression of syndecan-1 (CD138) is correlated with morphologic phenotype (epithelioid or spindle) of cultured tumour cells.

MATERIALS AND METHODS

Fifty-seven different soft tissue tumours were selected to analyse their syndecan-1 (CD138) reactivity. Immunohistochemical staining of paraffin sections, following a high temperature unmasking technique, was performed. The intensity and the pattern of staining was studied.

RESULTS

Cell membrane positivity was observed in epithelioid sarcomas and epithelial elements of synovial sarcomas. GISTs, some malignant epithelioid schwannoma and some fibromatosis showed intracytoplasmatic reaction, while pyogenic granuloma, Kaposi's sarcoma, fibrosarcoma and dermatofibrosarcoma protuberans were negative.

CONCLUSION

At first it seemed that the cell membrane positivity of syndecan-1 accompanied true epithelial differentiation in soft tissue sarcomas, but the results further highlighted the non specific nature of this expression. Therefore the heterogeneity in the appearance of syndecan-1 in various soft tissue tumours is not simply associated with the phenotype, suggesting more complex functions.

Proliferation and apoptosis within the oral mucosa "hemangiomas"

In the study the expression of Ki-67, p53, bcl-2 and apoptotic index in ten cases of lobular capillary hemangioma (LCH), ten of capillary hemangioma (CH), and five of epithelioid hemangioma (EH) was examined. The expression of Ki-67, p53 and bcl-2 did not differ significantly between each group of lesions. Instead, significant differences in apoptotic index between LCH and CH were found. The expression of bcl-2 was positively correlated with that of Ki-67 in LCH and CH group, but negatively correlated in the EH group. Our results confirm that LCH, EH and CH, which are histologically similar, are different in terms of proliferation/apoptosis balance. This reflects their different biology, and presumably pathogenesis.

Apoptosis and expression of Bax/Bcl-2 proteins in pyogenic granuloma: a comparative study with granulation tissue and capillary hemangioma

BACKGROUND

Pyogenic granuloma (PG) has been regarded as a florid expression of granulation tissue (GT) proliferation and shows distinct biological behavior compared to conventional GT. PG has not been examined from a standpoint of apoptosis.

METHODS

PG (15 cases), GT (14 cases) and capillary hemangioma (CH, 8 cases) were compared using in situ 3'-tailing reaction (ISTR), a histochemical method for identifying apoptotic cells, and immunohistochemistry for Ki-67, Bcl-2 and Bax proteins, in order to clarify and involvement of apoptosis in the difference of biological characteristics between PG and GT.

RESULTS

PG showed significantly lower ISTR-labeling indices than GT and CH and more frequent Bcl-2/Bax expression than GT, whereas Ki-67-labeling indices were variable from case to case and did not show any significant differences among any groups.

CONCLUSIONS

It is consequently suggested that the low apoptotic rate in PG is closely related to its characteristic rapid growth and is regulated by Bcl-2 family proteins.

The detection and comparison of angiogenesis-associated factors in pyogenic granuloma by immunohistochemistry

BACKGROUND

Pyogenic granuloma is a benign inflammatory lesion demonstrating obvious activity of angiogenesis. Female steroid hormones are believed to play important roles in the etiology because the lesion is frequently found in females with high levels of sex hormones. Few molecular mechanisms of the pathogenesis have been proposed and proven. The purpose of this study was to detect and compare the expression of angiogenesis-associated factors among healthy gingiva, gingiva from periodontitis, and pyogenic granuloma to clarify the pathogenesis of pyogenic granuloma.

METHODS

Fifteen specimens were collected from each of 3 groups of gingiva (healthy gingiva, periodontitis, and pyogenic granuloma). The subjects were age and gender matched. The specimens were processed for immunohistochemistry to detect and compare the expression of 2 angiogenesis enhancers, i.e., vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), 2 angiogenesis inhibitors, i.e., angiostatin and thrombospondin-1 (TSP-1), and estrogen receptor (ER). Using the subject as the unit of statistical analysis, either analysis of variance or chi-square analysis was employed to show the statistically significant difference at a level P <0.05.

RESULTS

The pyogenic granuloma group expressed significantly more VEGF and bFGF than healthy gingiva and periodontitis. The positive staining of VEGF was mostly localized in the cytoplasm of macrophages and fibroblasts while that of bFGF was in the extracellular matrix of lamina propria. Angiostatin was expressed significantly less in pyogenic granuloma than the other 2 groups and was mostly localized in the nuclei of endothelial cells and epithelial cells. There was no significant difference in the expression of TSP-1 and ER among the 3 groups.

CONCLUSIONS

The results of this research suggest that the etiology of pyogenic granuloma is due to the imbalance between angiogenesis enhancers and inhibitors. Whether and how the angiogenesis-associated factors are regulated by female steroid hormones remain to be answered.

The urokinase plasminogen activator system in angiosarcoma, Kaposi's sarcoma, granuloma pyogenicum, and angioma: an immunohistochemical study

Background Extracellular matrix proteolysis is one of the most important steps in angiogenesis. The urokinase-type plasminogen activator system (uPAS), consisting of the urokinase plasminogen activator (uPA), the uPA receptor (uPA-R), and their corresponding inhibitors, PAI-1 and PAI-2, is thought to play a role in this process.

METHODS

We investigated the expression of the components of uPAS in angiosarcoma (AS, n = 4), Kaposi's sarcoma (KS, n = 31), granuloma pyogenicum (GP, n = 25), angioma (AN, n = 15), and healthy controls (CO, n = 15) with immunohistochemical methods.

RESULTS

We found positive immunostaining for uPA-R and uPA in all cases of AS. Only two of four cases were positive for PAI-1, whereas all cases were negative for PAI-2. In KS, we observed positive immunostaining in 16 of 31 (51.6%) cases for uPA-R, in 11 of 31 (35.5%) cases for uPA, in 3 of 31 (9.6%) cases for PAI-1, and in 2 of 31 (6.4%) cases for PAI-2. The GP cases showed the following positive results: 4 of 25 (16%) for uPA-R, 6 of 25 (24%) for uPA, 10 of 25 (40%) for PAI-1, and 11 of 25 (44%) for PAI-2. Four cases (26.6%) of AN were positive for PAI-1 and five cases (25%) for PAI-2. In AN (n = 15), there was staining for neither uPA nor uPA-R. In none of the controls (n = 15) was immunostaining for the components of uPAS found in blood vessels.

CONCLUSIONS

uPAS is involved in malignant, benign, and reactive proliferative angiomatous lesions, but is absent in normal blood vessels. The upregulation of uPA and its corresponding receptor, uPA-R, in AS and KS supports the hypothesis of the proliferative nature of these lesions; however, the upregulation of the inhibitors (PAI-1 and PAI-2) in benign and reactive proliferative angiomatous lesions (GP and AN) shows how this process may be limited.

GLUT1: a newly discovered immunohistochemical marker for juvenile hemangiomas

Juvenile hemangiomas are common, benign vascular tumors of infancy. These lesions enlarge rapidly through cellular hyperplasia during the first year of life and then involute over several years. Distinctive histopathologic features of hemangiomas diminish during this evolution, and differentiation from vascular malformations becomes increasingly difficult. This distinction has important therapeutic implications, as juvenile hemangiomas differ from malformations in natural history and in potential for recurrence. We report here that high endothelial immunoreactivity for the erythrocyte-type glucose transporter protein GLUT1 is a specific feature of juvenile hemangiomas during all phases of these lesions. In a retrospective study, we found intense endothelial GLUT1 immunoreactivity, involving more than 50% of lesional microvessels, in 97% (139 of 143) of juvenile hemangiomas from patients aged 1 month to 11 years. No endothelial GLUT1 immunoreactivity was found in any of 66 vascular malformations (17 arteriovenous, 33 venous, 11 lymphatic, and 5 port-wine) from patients aged 5 days to 75 years, or in any of 20 pyogenic granulomas or 7 granulation tissue specimens. Abundant Ki-67 positivity in these latter lesions established that GLUT1 expression does not simply reflect mitotically active endothelium. Focal GLUT1 immunoreactivity was found in 3 of 12 angiosarcomas, but not in any of 5 hemangioendotheliomas (epithelioid or infantile kaposiform). These findings establish GLUT1 immunoreactivity as a highly selective and diagnostically useful marker for juvenile hemangiomas. Because high levels of endothelial GLUT1 expression in normal tissue are restricted to microvessels with blood-tissue barrier function, these findings also have implications for the molecular and developmental pathogenic mechanisms of juvenile hemangiomas.

Differential expression of connective tissue growth factor gene in cutaneous fibrohistiocytic and vascular tumors

Connective tissue growth factor (CTGF) is a member of a family of immediate early gene products that may play an important role during tissue regeneration, wound repair and skin fibrosis. In this study, CTGF gene expression in mesenchymal tumors was investigated by in situ hybridization and CD34 antigen expression was studied by means of immunohistochemical staining. CTGF mRNA was expressed in fibroblasts of all nine dermatofibromas examined, but five of seven dermatofibrosarcoma protuberans (DFSP) or two cases of malignant fibrous histiocytoma were negative for its expression. In contrast, CD34 antigen was expressed only in DFSP. In vascular tumors, CTGF mRNA was expressed in pyogenic granuloma but not in angiosarcoma. In addition, the endothelial cells in angiolipoma and angioleiomyoma, but not in venous lake, expressed CTGF mRNA. These vascular lesions were all positive for CD34 expression. Tumors of other origins were negative for CTGF mRNA. Our findings indicated that benign fibroblasts and/or vascular endothelial cells have the capability to express CTGF mRNA when activated, but these cells lose this ability when they achieve malignant potency. Thus, examination of CTGF gene expression may be useful for differentiating between benign and malignant mesenchymal tumors, or to determine the origin of the tumors in connective tissue.

Kaposi's sarcoma tumor cells preferentially express Bcl-xL

Several recently identified proteins such as Bcl-2 and Bcl-x have been found to regulate programmed cell death (i.e., apoptosis). In this report, we examined the levels of expression of proteins that can either prevent apoptosis (i.e., Bcl-2 or the long form of Bcl-x, designated Bcl-x1) or promote apoptosis (i.e., Bax or the short form of Bcl-x, designated Bcl-xs) in proliferating benign and malignant endothelial cells (ECs). In normal skin with quiescent ECs, no detection by immunohistochemical staining was observed for Bcl-xL, Bcl-xs, or Bcl-2. However, in diseased skin samples that feature a prominent angiogenic response such as in psoriasis or pyogenic granulomas, the proliferating ECs markedly overexpressed Bcl-xL, with little to no Bcl-2. In an acquired-immune-deficiency-syndrome-related neoplasm, Kaposi's sarcoma, the spindle-shaped tumor cells also overexpressed Bcl-xL compared with Bcl-2. These in vivo studies were extended in vitro using cultured ECs and Kaposi's sarcoma tumor cells that were examined by flow cytometry and immunoblot analysis. Both cultured ECs and Kaposi's sarcoma tumor cells express significantly higher levels of Bcl-xL than Bcl-2. Such overexpression of cell survival gene products may contribute to prolonging the longevity of EC-derived cells in several different benign and neoplastic skin disorders that are characterized by a prominent angiogenic tissue response.

High frequency of apoptosis in infantile capillary haemangioma

Infantile capillary haemangioma (ICH) is a well-established clinicopathological entity which often regresses spontaneously. To elucidate the cause of spontaneous involution of ICH, the apoptotic and proliferative activities in seven cases of ICH were compared with those in five cases of lobular capillary haemangioma (LCH), using formalin-fixed paraffin-embedded tissue sections. The number of apoptotic cells detected by the modified in situ end-labelling method was significantly higher in ICH than in LCH, while the proliferative activities evaluated with mitosis and Ki-67 antigen expression did not differ significantly. Lewisy (Ley) antigen, an apoptosis-associated marker, was expressed in all cases of ICH but in none of LCH, while labelling for p53 protein and bcl-2 protein was almost completely negative in both tumours. These findings clearly demonstrate a much higher apoptotic activity in ICH than in LCH and suggest that apoptosis might be a cause of the spontaneous involution of ICH.

Pyogenic granuloma of the cornea: report of a case and review of the literature

BACKGROUND

Pyogenic granulomas are ulcerated vascular proliferations, often accompanied by inflammatory infiltrates, which rarely affect the eye. Only few reports on pyogenic granulomas of the cornea have been presented.

METHODS

The enucleated globe containing the corneal tumor was examined histopathologically, and special immunohistochemical stains were performed.

RESULTS

The lesion had a yellowish appearance with marked vascularization. The inflammatory infiltrate was mainly composed of mononuclear cells, with no multinucleated giant cells, and was located anterior to Bowman's layer, leaving the corneal stroma unaffected. Immunohistochemical studies outlined the high vascular content, even in dense cellular areas, and confirmed the inflammatory nature of the mononuclear infiltrates.

CONCLUSIONS

Pyogenic granuloma of the cornea represents a clinical and morphological entity developing in a traumatized eye with corneal vascularization. Although the origin of these lesions remains obscure, there have been no signs of malignancy. Therefore, enucleation of an eye with a pyogenic granuloma should be avoided.

An intestinal counterpart of pyogenic granuloma of the skin. A newly proposed entity

Pyogenic granuloma is a common disease in the skin, but it is extremely rare in the gastrointestinal tract except for the oral cavity. We have seen three lesions (from three patients) of an intestinal counterpart of pyogenic granuloma and have reviewed their clinicopathologic features. Macroscopically, all three lesions revealed a polypoid growth with either a sessile or pedunculated configuration. All had an ulceration on the top. Microscopically, all these lesions were composed of a lobular proliferation of varying sizes of capillaries with an edematous stroma. Endothelial cells of the capillaries were swollen variously and in one case revealed a few mitotic figures. An inflammatory process was associated with the presence of ulcerations. Immunohistochemically, both Factor VIII-related antigen and QB-end/10(CD34) were positive only for the endothelial cells in all three cases. The characteristic macroscopic and histologic features thus allow for an early diagnosis of pyogenic granuloma in the gastrointestinal tract, which is similar to that observed in the skin.

Expression of VE (vascular endothelial)-cadherin and other endothelial-specific markers in haemangiomas

Haemangiomas are vascular tumours characterized by rapid growth and increased endothelial turnover. VE-cadherin is a recently discovered endothelial cell-specific cadherin located at intercellular junctions. In different types of epithelial tumours, cadherin expression is inversely correlated with invasiveness and metastatic dissemination. In this immunohistochemical study, VE-cadherin expression has been analysed in different types of haemangioma. VE-cadherin is highly expressed in endothelial cells of haemangiomas and is decreased, but still detectable, in some cases of haemangionendothelioma and angiosarcoma. The antigenic profile of most haemangioma cells was similar to that of normal endothelium. CD31, CD34, ICAM-1, von Willebrand factor, and VLA integrins were expressed in haemangioma endothelium; in addition, the major components of vascular basement membrane, namely fibronectin, collagen type IV, and laminin, were correctly expressed and organized. Surprisingly, a marked reactivity for the M form of laminin (merosin) was detected in the basement membranes of two juvenile capillary haemangiomas. Overall, this study shows that, with the exception of angiosarcoma and haemangionendothelioma, vascular tumours maintain most of the differentiation characteristics of normal endothelium. This encourages speculation that in these pathologies, abnormal endothelial proliferation is more related to the release of local factors than to an altered endothelial phenotype.

Identification and semiquantification of estrogen and progesterone receptors in pyogenic granulomas of pregnancy

Cases of pyogenic granuloma in pregnant women, nonpregnant women, and men were evaluated for the detection of estrogen and progesterone receptor proteins by immunoperoxidase staining. Immunostaining for estrogen receptors revealed a marked immunoreactivity of the endothelium within lesional tissue and in the overlying mucosal epithelium in many cases. Progesterone receptor immunoreactivity was only present within the epithelium, where it was much less than that of estrogen receptor immunoreactivity in both quantity (proportion of positive cells) and intensity. No characteristic staining pattern or significant quantitative difference among the three study groups could be discerned. These findings suggest that the quantity of estrogen or progesterone receptors in pyogenic granuloma is not the determining factor in the pathogenesis of this lesion. Rather, such a role may be attributed to the levels of circulating hormones. The levels of estrogen and progesterone are markedly increased in pregnancy and could therefore exert a greater effect on the endothelium of the pyogenic granuloma.

Immunohistochemical localization of p53 protein in malignant hemangioendothelioma

The immunohistochemical localization of p53 protein was examined in skin tissue sections, including normal vascular endothelial cells and the skin tissue sections from lesions of granuloma telangiectaticum with proliferation of vascular endothelial cells and malignant hemangioendothelioma, a malignant tumor originated from vascular endothelial cells. It was found that p53 protein was positive in 2 out of 4 cases of malignant hemangioendothelioma. Thus, immunohistochemical detection of p53 protein proved useful in the diagnosis of malignant hemangioendothelioma.