[Dysphagia caused by ossification of the anterior longitudinal ligament associated with diffuse idiopathic skeletal hyperostosis: report of 2 cases].

Two cases of ossification of the anterior longitudinal ligament (OALL) associated with diffuse idiopathic skeletal hyperostosis (DISH) presenting as dysphagia are reported. DISH has long been regarded as a radiological entity manifesting flowing ossification adjacent to the anterior and lateral borders of at least four contiguous vertebral bodies, maintenance of disc spaces, and a dearth of bony ankylosis and erosion of the apophyseal and sacroiliac joints. In the majority of cases, this entity shows an innocuous clinical course, but the dysphagia shown in our cases has also been documented in previous literature. Case 1 was a 63-year-old male developing progressive dysphagia and rhinolalia. Cervical X-rays and CT showed flowing OALL in the entire cervical spine. MRI demonstrated displacement of the trachea and esophagus by this mass. There was OALL in the thoracic and lumbar spine. Case 2 was a 62-year-old male who had undergone removal of ossification of the posterior longitudinal ligament (OPLL) from C2 to C5. He developed dysphagia and myelopathy. Cervical X-rays and CT demonstrated projection of OALL as well as posterior osteophytes at C5/6. MRI suggested that OALL had caused dysphagia, and osteophytes deteriorated myelopathy. Removal of OALL was carried out in these two cases. In case 2, removal of the osteophytes and herniated disc was carried out at the same time. Postoperative course was unremarkable with improvement of symptoms. Treatment of dysphagia due to OALL is considered to be conservative. However, surgical decompression should be considered in cases of marked projection of OALL obstructing the esophagus as shown in our cases.