Thymoma-Related Chest Pain and Dyspnea in a Middle-Aged Caucasian Female With Myasthenia Gravis and Good's Syndrome: A Case Report.

Thymomas are rare tumors originating from thymic tissue, often associated with various paraneoplastic syndromes that can pose significant clinical management challenges. Myasthenia gravis, one of the most common paraneoplastic syndromes linked to thymomas, is characterized by autoantibodies targeting the neuromuscular junction, leading to muscle weakness exacerbated by repetitive use. Good's syndrome, an adult-onset immunodeficiency associated with thymomas, results in hypogammaglobulinemia and susceptibility to opportunistic infections, which can be life-threatening. We present the case of a 57-year-old Caucasian female with no prior medical history, who presented with a three-month history of progressive chest pain, dyspnea, and muscle weakness. A computed tomography (CT) scan of the chest revealed an anterior mediastinal soft tissue mass. Upon admission, a diagnostic workup, including serum anti-acetylcholine receptor antibodies and electromyography, confirmed the diagnosis of myasthenia gravis. Immune studies revealed hypogammaglobulinemia, consistent with Good's syndrome. The patient underwent complete surgical resection of the thymoma and received intravenous immunoglobulin (IVIG) therapy. This case report highlights the rarity and clinical significance of concurrent myasthenia gravis and Good's syndrome as paraneoplastic manifestations secondary to thymoma. Given the incidence of thymoma-associated paraneoplastic syndromes, early recognition and intervention are crucial for optimal outcomes. Future research may further elucidate the mechanisms underlying these associations, guiding improved management strategies.