Published online Jul 28, 2015. doi: 10.5320/wjr.v5.i2.176
Peer-review started: September 26, 2014
First decision: December 17, 2014
Revised: April 18, 2015
Accepted: April 28, 2015
Article in press: April 30, 2015
Published online: July 28, 2015
Thymic carcinomas are rare tumors of the thymus arising in the thymic epithelium. They represent less than 1% of thymic malignancies. They often present with an advanced disease and metastasize to regional lymph nodes and distant sites. They have a worse prognosis with a 5-year survival rate of 30%-50%, while thymomas are much less invasive and have a 5-year survival of approximately 78%. We report a rare form of clinical presentation of a thymic carcinoma in which the diagnosis of myasthenia gravis was the cornerstone of the diagnosis of cancer. Surgery is considered the salvage treatment when possible. Radiotherapy is a second choice of salvage treatment, when possible depending on its localization and relation to nearby structures such as vascular structures. Molecular target therapy is a more directed, more expensive but less toxic treatment. Further studies need to be carried out for its approval worldwide, outside clinical trials.
Core tip: We report a rare form of clinical presentation of a thymic carcinoma in which the diagnosis of myasthenia gravis was the cornerstone of the diagnosis of cancer. Surgery is considered the salvage treatment when possible. Radiotherapy is a second choice of salvage treatment, when possible depending on its localization and relation to nearby structures such as vascular structures. The prognosis is very reserved, when neither surgery nor radiotherapy can be accomplished. Having an unfavorable molecular signature, less than 10% of thymic carcinomas have c-kit mutations, and clinical outcome of these patients is detrimental.