石灰化を伴った多房性胸腺囊胞の1例

Multilocular Thymic Cyst with Calcification；Report of a Case

はじめに　胸腺囊胞はその多くが単房性である．多房性胸腺囊胞は炎症に起因するとされ，石灰化を呈するものはまれとされている1，2）．われわれは，術前奇形腫との鑑別が困難であった石灰化を伴う多房性胸腺囊胞の1切除例を経験したので報告する．

A female in her 40s was admitted with an abnormal shadow on chest X-ray. A chest computed tomography （CT） revealed an anterior mediastinal cystic mass with calcification. We suspected the tumor to be a teratoma, and surgery was performed. The tumor was connected with the thymus, and did not infiltrate to the surrounding tissues. Macroscopically, the cyst was multiloculated with fibrous walls. Microscopically, thymic tissue was noted in the cyst wall, with neither thymic epithelial tumor nor teratoma. The cyst wall contained collagen fibers, cholesterol clefts, and calcification. Based on these findings, the tumor was diagnosed as multilocular thymic cyst with calcification.