Thymoma-Associated Systemic Lupus Erythematosus and Myasthenia Gravis

Area of Science:

• Oncology
• Immunology
• Rheumatology

Background:

• Thymomas, rare tumors of thymic epithelial cells, disrupt immune tolerance and can cause autoimmune diseases.
• Myasthenia gravis (MG) is a common thymoma association, but links to rheumatic diseases like systemic lupus erythematosus (SLE) are less frequent.

Purpose of the Study:

• To present a case of a patient with SLE who developed thymoma and MG.
• To discuss the diagnostic challenges of overlapping autoimmune disorders and the importance of identifying underlying malignancies.

Main Methods:

• A 32-year-old female patient with diagnosed SLE presented with symptoms suggestive of MG.
• Diagnostic workup included laboratory tests (anti-acetylcholine receptor antibodies) and chest CT scan revealing an anterior mediastinal mass.
• A CT-guided biopsy confirmed thymoma (WHO type AB).

Main Results:

• The patient was diagnosed with SLE, MG, and thymoma.
• Treatment involved prednisone, pyridostigmine, and IV immunoglobulin for MG, followed by neoadjuvant chemotherapy, surgery (thymectomy, pericardiectomy, venorrhaphy, pneumorrhaphy), and radiation therapy for thymoma.
• At 12-month follow-up, MG symptoms resolved, and SLE remained stable with only arthralgias.

Conclusions:

• This case underscores the diagnostic complexity of co-occurring autoimmune conditions.
• It emphasizes the necessity of thorough evaluation for malignancies, such as thymoma, in patients with atypical or evolving autoimmune symptoms.