Peritoneal "Melanosis" associated with a ruptured ovarian dermoid cyst: Report of a case with electron-probe energy dispersive x-ray analysis

A case of peritoneal "melanosis" due to a ruptured left ovarian dermoid cys t is described. Histology showed that the dermoid contained gastric mucosa associated with ulceration, necrosis, and hemorrhage. The areas of pigmenta tion within the dermoid, omentum, and peritoneal cavity were due to collect ions of heavily pigment-laden macrophages. The pigment lacked the histochem ical features of either melanin or hemosiderin, but electron-probe energy d ispersive x-ray analysis showed that the pigment contained a high concentra tion of iron. It is postulated that peptic ulceration with hemorrhage is th e most likely source of the pigment and that the peritoneal pigmentation is secondary to spillage of the contents of the dermoid cyst.