外周型角化囊性瘤的影像学特征

CT and MR imaging features of peripheral keratocystic odontogenic tumors

目的：分析2例面侧深区外周型角化囊性瘤的CT及MRI影像学表现特征，并通过文献回顾，分析外周型角化囊性瘤的解剖部位、流行病学及影像学特征。为临床诊断提供参考。方法：19例外周型角化囊性瘤（包括文献报道的17例及本文报告的2例），16例发生于牙龈，1例发生于颊间隙，2例发生于面侧深区。分析1例颊间隙及2例面侧深区病变的CT图像、1例面侧深区病变的MRI图像、9例牙龈及1例颊间隙病变的x线图像特征。结果：患者年龄37．83岁，平均年龄56．5岁，男女比例为1：1．285。外周型角化囊性瘤多发生于牙龈（84．2％1，颊间隙f5．2％）及面侧深区f10．5％）罕见。CT及MRI是检查外周型角化囊性瘤的有效方法，均表现为囊性病变，MRI可对病变囊腔内成分做进一步分析。除1例病例x线表现为相邻牙槽骨压迫吸收外，其余病变在x线上均无特异表现。结论：面侧深区是外周型角化囊性瘤罕见的发生部位。在CT、MRI图像上．位于面侧深区的囊性改变，应该考虑外周型角化囊性瘤的可能。

PURPOSE： Peripheral keratocystic odontogenic tumor （PKCOT） is a rare entity and the imaging findings have not been reported. The aim of this study was to explore CT and MR imaging characteristics of two PKCOTs in lateral facial deep region （LFDR）, and review their clinical and radiological characteristics. METHODS： Nineteen PKCOTs were found, including seventeen from the literatures and two new cases reported in the present study. Sixteen of them were located in the gingiva, one in the buccal space and two in LFDR. CT imaging features were based on one PKCOT in the buccal space and two in LFDR. MR imaging features were detected on one PKCOT in LFDR, and conventional radiographic characteristics were determined on nine PKCOTs. RESULTS： The patients aged from 37 to 83 years, with a mean age of 56.5 years. The male to female ratio was 1：l.285, with no predilection for either gender. Buceal space （5.2%） and LFDR （10.5%） were relatively rare original sites for PKCOTs, compared with gingiva （84.2%）. PKCOTs were clearly depicted on CT and MR imaging as they had cystic changes. Contents of the cysts were further analyzed by using different series of MRI. No radiological features were found on radiographs except one with minimal bone resorption in the alveolar crest. CONCLUSIONS： LFDR is a rare original site for PKCOT. PKCOT should be included as one of differential diagnosis of cystic lesions found in LFDR on CT and MR imaging.