Recurrence and Malignant Transformation of Thymoma After 26 Years – A Rare Presentation

Thymoma is a mediastinal tumour with malignant potential, which has a recurrence rate after complete resection ranging from 5 to 50 %. It is an epithelial neoplasm of the thymus, which commonly lies in the anterior mediastinum. Here we present an interesting case of a 58 year old female patient on treatment for Myasthenia Gravis for the past 26 years. She had undergone thymectomy with dissection of pericardium and adjacent pleura 26 years back. Now she had presented with worsening myasthenia symptoms, underwent treatment comprising of steroid pulse therapy and plasmapheresis along with regular medications. She was evaluated for left lung collapse, which revealed a thymoma involving left lung and a solitary deposit on the right side probably metastasis. Though the recurrence rate of thymoma is high, this case is unique as it recurred as malignant thymoma after 26 years.