INCREASED ATTENUATION IN ODONTOGENIC KERATOCYSTS WITH COMPUTED-TOMOGRAPHY - A NEW FINDING

An increased attenuation area (IAA) is sometimes seen in the cystic ca vity of odontogenic keratocysts (OKCs) on CT scans. The significance o f IAA was compared radiologically and histologically in 26 cysts in wh ich a provisional diagnosis of OKC has been made. First, the presence of IAA in the cystic cavity was assessed. Then, relationship between t he presence of IAA and data obtained from the cysts, including the CT and histological findings and the visual appearance of the cyst conten ts, was evaluated. An IAA was frequently seen in large multilocular cy sts. There was no relationship between the presence of IAA and aggress ive features of the cyst on CT or the cyst contents. Histologically, s ubepithelial inflammation was, often observed in the cysts with IAA. I n order to ascertain whether the IAA was due to the keratin mass, a CT scan of a bundle of hair in a water bath was performed and shown to h ave a similar density. Our study demonstrated that IAA in cystic cavit ies results from desquamated keratin. Since this seems to occur in lon g-standing or inflamed multilocular OKCs, it could be used as a signif icant finding in the diagnosis of OKC.