Figure 3.

(A) Histological examination showed typical myxomatous tissue (lower left) adjacent to papillary frond-like structures very reminiscent of papillary fibroelastoma (upper right, note intervening thrombotic material). (B) Papillary structures alternating with hyperchromatic myxoma cells, note myxomatous cores within some papillae. (C) Elastica van Giesson stain in this area of the tumor was indistinguishable from PFE with some darkly staining granular elas-totic material. (D) Higher magnification of the papillae showed minute myxomatous foci (note residual bleeding and fibrin in some papillae). (E) The tumor in other areas displayed classical myxomatous appearance and expressed strongly calretinin (subimage). (F) Calretinin immunostaining highlighted myxoma cells covering the papillae and within papillary cores (note non-staining flat endothelial cells covering the papilla on the left).