Small thymomas and myasthenia gravis: a poorly understood association.

Myasthenia gravis (MG) is associated with about 20% of all patients with thymomas, but the occurrence in patients with small thymomas is rare. The pathogenetic relevance of these small thymomas for MG is poorly understood until now. We report on the clinical course of a 39-year-old female patient suffering from MG and undergoing thymectomy for a small thymoma and discuss the pathogenetic importance of small thymomas for MG.