1994 Volume 8 Issue 2 Pages 117-123
Six cases of thymic cyst in our hospital were studied, clinicopathologically. The 6 cases of thymic cyst consisted of9.7% of all mediastinal tumors, 14.3 % of thymus related tumors and 60.0% of congenital cysts.
CT and MRI were most useful for diagnosis of thymic cyst. The internal density of the tumor showed from -10 to 20 Hounsfield unit in CT and dark signal intensities inT1 and bright signal intensities in T2 weighted image of MRI. But, definitive diagnosis was oftendifficult. The preoperative diagnosis of six were thymic cyst in one case, thymus related with MG in 2 cases, thymoma in one case and pericardial cyst in 2 cases.
Pathological examination showed the epithelial cells and thymic tissues with Hassal's body in the cyst wall, but in one case incidental thymoma was recognized beside the cyst wall.
All cases of thymic cyst were resected and they were well and alive with no evidence of recurrence. It was concluded that thymic cyst should be carefully managed because of the difficulty of diagnosis, complications of incidental thymoma, malignant transformation and rupture of the cyst with intracystic bleeding.
