Rokitansky nodule

In the vast majority (88%), dermoid cysts are uni-lociflar cystic lesions filled with sebaceous material. A protuberance, the Rokitansky nodule, or dermoid plug, projects into the cavity and is the hallmark of dermoids (Fig. 9.17). It contains a variety of tissues, often including fat and calcifications, which represent teeth or abortive bone. Fat is detected in over 90%,... 

A minority of dermoid cysts will demonstrate no fat or only small foci of fat within the wall or the Rokitansky nodule (Fig. 9.28) [73]. Yamashita et al. reported that 15% of mature teratomas did not show fat within the cystic cavity. Approximately half of these cases displayed small amounts of fat within the wall of the dermoid or the dermoid plug. In 8% of henign teratomas, no fat could be detected [73]. 

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