Fig. 4

Macroscopic and microscopic findings of the resected specimen. a (left-hand): Macroscopically, a dark-red solid protuberance was found in the cyst wall (arrow). a (right-hand): Macroscopically, a thickened portion of the cyst wall where the dorsal mural nodule seemed to have originally existed was detected (arrowhead). b, c Hematoxylin and eosin staining showed that the cyst wall mainly consisted of thick fibrous stroma and the ventral mural nodule consisted of several sizes of blood-filled vascular cavities surrounded by endothelial cells within the organized hematoma (original magnification: b × 40, c × 100). d, e Hematoxylin and eosin staining showed that the thickened portion of the wall consisted of malformed veins of various sizes within the calcified hematoma (original magnification: d × 40, e × 200)