Fig. 5

Immunostaining of the cyst wall. Both the spindle cells lining the cyst and those lining the mural blood vessels exhibit positive (brown) intracytoplasmic staining for CD31 (a) and von Willebrand Factor (b). This indicates a vascular origin of the cyst. c LYVE-1 staining of the cells lining the cyst wall is positive and varies from weak to moderate intracytoplasmic staining (brown). Note that the endothelial cells lining the blood vessel in the central papillary projection of cyst wall are negative. d PROX-1 staining of the cells lining the cyst wall is positive showing moderate to strong intranuclear staining (brown). Note the endothelial cells lining the blood vessel in the central papillary projection of cyst wall are negative