Overexpression of Vascular Endothelial Growth Factor A in Invasive Micropapillary Colorectal Carcinoma.

BACKGROUND: Invasive micropapillary carcinoma (IMPC) is a rare variant of colorectal cancer with an adverse prognosis. "Retraction artifact" around tumor cells is a feature of IMPC. The aim of this study was to assess the nature of the retractions around the tumor cells and to describe the histopathological features of a group of 18 cases of IMPC. METHODS: A pathology review of 128 consecutive colorectal cancers identified 18 cases of histologically proven IMPC using 5% of the total tumor volume comprised of a micropapillary component as the diagnostic criterion. Immunostains for D2-40, CD31, CD34, vascular endothelial growth factor A (VEGF-A), and mucin 1 (MUC-1) were performed using the avidin-biotin complex method. RESULTS: Cases of IMPC were characterized by pseudomicropapillae surrounded by lacunar-like clear spaces. These structures exhibited the inside-out growth pattern as highlighted by MUC-1 staining. The lining of the lacunar spaces was immunoreactive to CD31 but not CD34 or D2-40, indicating that they are neovascular structures. Furthermore, the tumor cells strongly and diffusely expressed VEGF-A. CONCLUSIONS: The strong coexpression of VEGF-A and CD31 suggests a prominent role of neoangiogenesis in these tumors.

Gangliocytic paraganglioma of the appendix with features suggestive of malignancy, a rare case report and review of the literature.

We report a case of appendicial paraganglioma in a 40 year old female who presented with acute appendicitis and underwent laparoscopic appendectomy. To the best of our knowledge this is the first reported case of appendicial gangliocytic paraganglioma with features suggestive of malignancy in the modern literature. Van Eeden S. et al. reported the first case of appendicial paraganglioma in a 47 year old man who also presented with acute appendicitis. The appendectomy specimen showed a distended appendix with thickened wall, and a 1.3 cm mucosal based yellow lesion. Microscopically this lesion was centered in the submucosa and consisted of three different cell types: (a) epithelioid cells with pale eosinophilic finely granular cytoplasm containing bland oval nucleus with stippled chromatin, that form solid nests lying in a trabecular pattern and in formations reminiscent of 'Zellballen' as seen in paragangliomas (b) second type cells have large vesicular nuclei with prominent nucleoli and abundant cytoplasm that are scattered singly, (c) third type cells with bland elongated nuclei form broad fascicle and envelop the epithelioid and ganglion cells. Immunohistochemical analysis showed the epithelioid cell nests immunoreactive for synaptophysin and the ganglion-like cells and spindle Schwann cells to be immunoreactive for S100 protein, whereas all three cells populations were negative for CAM5.2 and Pancytokeratin. We do believe that an accurate diagnosis of Gangliocytic paraganglioma (GP) of the appendix was rendered, detailed microscopic examination of doubled hematoxylin and eosinophil stained sections as well as the immunohistochemical phenotype of the three components have been undertaken to confirm the diagnosis of GP.

Concurrent Paget's disease and basal cell carcinoma of the vulva; a case report.

An 82-year-old Caucasian woman had a long-standing history of recurrent Paget's disease of the right perianal region that was documented by multiple skin biopsies. Histological examination of a skin biopsy from an erythematous raised right perianal area revealed large rounded cells with ample pale staining cytoplasm scattered throughout the epidermis in multifocal nests and a flattened basal layer. A second lesion showed tongues of basaloid cells with peripheral palisading in continuity with the undersurface of the epidermis at multiple points. The individual tumor nests had cytoplasmic melanization and slit-like stromal separation. The tumor cells in the epidermis showed positive immunoreactivity for carcinoembryonic antigen while the basaloid cells were negative. A diagnosis of combined vulvar Paget's disease and basal cell carcinoma of an infundibulocystic type was rendered. Concurrent involvement of the same area by Paget's disease and Basal cell carcinoma (BCC) has been reported only once. Here we report a second case of BCC concurrent with vulvar Paget's disease.

Endothelial caveolin-1 regulates pathologic angiogenesis in a mouse model of colitis.

BACKGROUND & AIMS: Increased vascular density has been associated with progression of human inflammatory bowel diseases (IBDs) and animal models of colitis. Pathologic angiogenesis in chronically inflamed tissues is mediated by several factors that are regulated at specialized lipid rafts known as caveolae. Caveolin-1 (Cav-1), the major structural protein of caveolae in endothelial cells, is involved in the regulation of angiogenesis, so we investigated its role in experimental colitis. METHODS: Colitis was induced by administration of dextran sodium sulfate to wild-type and Cav-1(-/-) mice, as well as Cav-1(-/-) mice that overexpress Cav-1 only in the endothelium. Colon tissues were analyzed by histologic analyses. Leukocyte recruitment was analyzed by intravital microscopy; angiogenesis was evaluated by immunohistochemistry and in vivo disk assays. RESULTS: Cav-1 protein levels increased after the induction of colitis in wild-type mice. In Cav-1(-/-) mice or mice given a Cav-1 inhibitory peptide, the colitis histopathology scores, vascular densities, and levels of inflammatory infiltrates decreased significantly compared with controls. Lower levels of leukocyte and platelet rolling and adhesion colitis also were observed in Cav-1(-/-) mice and mice given a Cav-1 inhibitory peptide, compared with controls. Cav-1(-/-) mice that received transplants of wild-type bone marrow had a lower colitis score than wild-type mice. Data from mice that overexpress Cav-1 only in the endothelium indicated that endothelial Cav-1 is the critical regulator of colitis. Genetic deletion or pharmacologic inhibition of endothelial Cav-1 also significantly decreased vascular densities and angiogenesis scores, compared with controls. CONCLUSIONS: Endothelial Cav-1 mediates angiogenesis in experimental colitis. Modulation of Cav-1 could provide a novel therapeutic target for IBD.

Differential angiogenic regulation of experimental colitis.

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders of the intestinal tract with unknown multifactorial etiology that, among other things, result in alteration and dysfunction of the intestinal microvasculature. Clinical observations of increased colon microvascular density during IBD have been made. However, there have been no reports investigating the physiological or pathological importance of angiogenic stimulation during the development of intestinal inflammation. Here we report that the dextran sodium sulfate and CD4+CD45RBhigh T-cell transfer models of colitis stimulate angiogenesis that results in increased blood vessel density concomitant with increased histopathology, suggesting that the neovasculature contributes to tissue damage during colitis. We also show that leukocyte infiltration is an obligatory requirement for the stimulation of angiogenesis. The angiogenic response during experimental colitis was differentially regulated in that the production of various angiogenic mediators was diverse between the two models with only a small group of molecules being similarly controlled. Importantly, treatment with the anti-angiogenic agent thalidomide or ATN-161 significantly reduced angiogenic activity and associated tissue histopathology during experimental colitis. Our findings identify a direct pathological link between angiogenesis and the development of experimental colitis, representing a novel therapeutic target for IBD.

Regulation of dextran sodium sulfate induced colitis by leukocyte beta 2 integrins.

Inflammatory bowel diseases (IBD) are chronic inflammatory disorders whose etiology remains unknown. Reports have shown that infiltration of leukocytes into intestinal tissue is a pathognomonic hallmark for this disease. Leukocyte beta(2) integrins are heterodimeric adhesion membrane proteins that are exclusively expressed on leukocytes and participate in immune cell adhesion and activation. In this study, we examined the pathophysiological role of the beta(2) integrins CD18, CD11a, and CD11b in the pathogenesis of dextran sodium sulfte (DSS)-induced experimental colitis. Disease activity was measured by daily assessment of clinical parameters including stool consistency, weight loss, occult blood, and gross rectal bleeding. Histopathological changes including severity of inflammation, surface epithelial/crypt damage, and depth of injury were also determined. The CD18 null and CD11a null mice had significantly lower disease activity and cumulative histopathological scores compared to wild-type mice. Interestingly, CD11b null mice did not show protection against DSS colitis and displayed increased disease activity compared to wild-type mice. Examination of specific leukocyte populations in the distal colon from various mice revealed significant attenuation of neutrophil and macrophage infiltrates in CD18, CD11a, and CD11b null mice. Surprisingly, the CD11b null mice showed a significant increase in plasma cell infiltration in response to DSS suggesting that this molecule may influence plasma cell function during colitis. This study demonstrates that genetic loss of CD18 or CD11a is protective during experimental colitis and that CD11b may serve a regulatory role during development of disease.