Fig. 6

Immunohistochemical analysis of two ES tumor specimens and control tissues for IL6, vimentin and smooth muscle actin (SMA). Pictures A and B show staining of control tissues with anti-IL6-ab (both 200×): a Appendix: positive staining of cells/extracellular space of lamina propria. b Tonsil: positive staining of cells/extracellular space in center of lymphoid follicles. Pictures C and D: examples of ES, negative and positive for IL6. c1 and c2 negative for IL6 in connective tissue septa within the tumor (Pt. 8). d1 and d2) positive for IL6 in connective tissue septa within the tumor (Pt. 7). In both samples no staining could be observed in tumor tissue. c1 and d1: 100×, c2 and d2: 200×. Pictures e1-e3: comparison of different stainings of ES, positive case (Pt. 7), all 200×): e1 IL6 staining, showing positivity in connective tissue septa between negative (blue) tumor cells. e2 Staining against vimentin demonstrates mesenchymal character of both tumor cells and cells in connective tissue septa. e3 Smooth muscle actin highlights the cells within the connective tissue septa, defining them as fibroblasts