Thymic carcinoma with myasthenia gravis: Two case reports

Area of Science:

• Oncology
• Neurology
• Thoracic Surgery

Background:

• Myasthenia gravis (MG) is typically associated with thymoma, not thymic carcinoma.
• Previous understanding suggested thymic carcinoma does not occur with MG.
• This study presents two unusual cases contradicting this notion.

Purpose of the Study:

• To report and analyze two unique cases of thymic carcinoma occurring in patients with myasthenia gravis.
• To discuss the implications of these findings on the understanding of thymic malignancies and their association with MG.

Main Methods:

• Detailed clinical presentation and diagnostic workup of two patients with thymic carcinoma and MG.
• Review of pathological findings, including World Health Organization (WHO) criteria for thymoma and carcinoma.
• Analysis of treatment strategies, including pharmacotherapy and surgical intervention.

Main Results:

• Case 1: A 54-year-old male with MG and anti-acetylcholine receptor antibody (ARAB) positive, diagnosed with a mixed thymoma (80%) and small cell carcinoma (20%).
• Case 2: A 51-year-old female with MG and ARAB positive, diagnosed with squamous cell carcinoma, showing suspected invasion of surrounding structures.
• Both patients were initially treated with pharmacotherapy for MG before surgical intervention for thymic carcinoma.

Conclusions:

• Thymic carcinoma can indeed be associated with myasthenia gravis, contrary to prior assumptions.
• These cases suggest thymic carcinoma may develop from pre-existing thymomas during long-term follow-up.
• The findings highlight the importance of considering thymic carcinoma in MG patients, even with initial pharmacotherapy management.