Thrombocytopaenia successfully treated by a multilocular thymic cyst resection.

The multilocular thymic cyst (MTC) is a rare, acquired disease caused by inflammatory changes in the thymus, and is associated with autoimmune diseases. We report a case of MTC with thrombocytopaenia, which improved following surgical resection. A 45-year-old man developed thrombocytopaenia with an anterior mediastinal tumour. Thrombocytopaenia due to an autoimmune mechanism, associated with thymoma or thymus-related disease, was suspected. Pathologic analysis following thoracoscopic thymectomy confirmed MTC. The platelet level recovered postoperatively. Our findings suggested a relationship between the acquired formation of MTC and the development of autoimmune antibodies. However, further investigation is needed to obtain more information.