Figure 2

Microscopic picture including immunohistochemical findings of the lesion. A: The convoluted thin part of the cyst wall formed by hyalinized paucicellular connective tissue. Noteworthy is the lack of any distinct lining of the cyst. Hematoxylin Eosin staining. Objective magnification: 10×. B: Numerous nerve bundles present in the cyst wall (arrows). Hematoxylin Eosin staining. Objective magnification: 10×. C: Nerve bundles marked with antibody against PGP 9.5. Noteworthy is the arrangement of the nerve elements and the cyst lining that suggests an intraneural formation of the cyst. PGP 9.5 immunohistostaining. Objective magnification: 10×. D: The nerve bundles as if “embracing” the cyst wall. S-100 immunohistostaining. Objective magnification: 10×. E: EMA immunopositivity is present within the cyst wall but the very inner surface is totally negative. EMA immunohistostaining. Objective magnification: 10×. F: The pattern of immunopositivity for D2-40 strongly follows that of EMA in some regions, which suggests a co-localization. D2-40 immunohistostaining. Objective magnification: 20×. G: CD31 immunopositivity (similarly like CD34 – next figure) is limited to the endothelial elements. CD31 immunohistostaining. Objective magnification: 10×. H: Antibody against CD34 (like for CD31) marks only vascular endothelium. The lining of the cyst is negative. CD34 immunohistostaining. Objective magnification: 10×.