Microthymoma in elderly-onset myasthenia gravis detected preoperatively

A 77-year-old woman with a 3-month history of muscle weakness was diagnosed with elderly-onset generalized myasthenia gravis (Myasthenia Gravis Foundation of America classification IIa) based on a high serum acetylcholine receptor antibody level (25.4 nmol·L–1) and neurological findings. Computed tomography detected a small nodule (diameter 15 mm) in the anterior mediastinum, which was suspected to be a thymoma. An extended thymectomy was performed. The pathological examination revealed a 6-mm-diameter thymoma, termed a microthymoma, accompanied with a unilocular thymic cyst without capsule formation (type B2 according to the World Health Organization classification). Some fat tissue was also found within the tumor.

Source: Asian Cardiovascular and Thoracic Annals - October 9, 2016 Category: Cardiology Authors: Hino, H., Nishimura, T., Seki, A., Nitadori, J.-i., Arai, T., Nakajima, J. Tags: Thoracic Source Type: research