颞下颌关节区滑膜软骨瘤病的CT诊断

CT Diagnosis of Synovial Chondromatosis in the Temporomandibular Joint

目的 探讨颞下颌关节区滑膜软骨瘤病在CT上的表现特点。资料与方法 搜集9例主诉为单侧颞下颌关节区肿胀患者的CT轴位和冠状位扫描,并对其CT表现进行评价。所有病例均经关节镜或手术病理证实为滑膜软骨瘤病。结果 颞下颌关节滑膜软骨瘤病的CT表现为:(1)关节区软组织肿大(n =8) ;(2 )病变内有散在钙化小体(n =8) ;(3)关节间隙增宽(n =4 ) ;(4)下颌髁突骨质异常改变(n =3) ;(5 )颞骨关节面骨质异常改变(n =6 ) ,其中CT表现为颞骨关节面骨质硬化者4例,颞骨关节面骨质吸收者3例,颞骨关节面骨质变薄者1例。1例CT检查显示滑膜软骨瘤病向上经颞骨关节面侵犯颅内(大脑颞叶脑膜)。结论 颞下颌关节滑膜软骨瘤病的CT表现以该区软组织肿胀伴散在的钙化小体和周围骨质受侵犯为特征。后者可以引起中颅窝底的破坏和颅内侵犯,进而影响病变的预后。

Objective The discuss the CT features of synovial chondromatosis of the temporomandibular joint (TMJ).Materials and Methods Nine patients who suffered from swelling in the unilateral TMJ region were examined with axial and coronal CT scans. All TMJ lesions were histopathologically confirmed to be synovial chondromatosis through both biopsy (arthroscopic punch technique) and operation. CT appearance of each lesion and the lesion involving the glenoid fossa were separately evaluated.Results The abnormal CT findings of synovial chondromatosis in the TMJ were observed as (1) soft tissue swelling (n=8), (2) loose calcified bodies (n=8), (3) widening of joint space (n=4), (4) mandibular condyle erosion (n=3), and (5) glenoid fossa erosion (n=6). Three manifestations of the glenoid fossa destruction were revealed on CT images: sclerosis of glenoid fossa (n=4), local resorption of articular surface of the temporal bone (n=3), and local thinning of glenoid fossa (n=1). One lesion with intracranial involvement through the dura of temporal lobe of cerebrum was noticed by CT. Conclusion On CT images, synovial chondromatosis of the TMJ is characteristic of loose cartilaginous bodies with the soft tissue swelling and bone destruction. It is believed that precise description of bony changes of the glenoid fossa may be valuable for assessing the aggressive tendency and prognosis of this condition.