Thymoma-Related Paraneoplastic Syndrome Mimicking Reactive Arthritis

Abstract

Background and Objectives: Thymomas are associated with a high frequency of paraneoplastic manifestations. Paraneoplastic syndrome (PNS) with thymoma presents a challenge to clinicians because of the need to decipher the association between the presenting symptoms and the underlying tumor. The condition most commonly noted in patients with PNS with thymoma is myasthenia gravis. Other common autoimmune diseases that may present as PNS include systemic lupus erythematosus, pure red cell aplasia, and Good syndrome. Seventy-six percent of patients with PNS-associated thymoma experience resolution of PNS after curing thymoma. Materials and Methods: A 37-year-old man with a two-month fever accompanied by polyarthritis accidently found thymoma after contrast computed tomography scans of his chest. He accepted Video assisted thoracoscopic surgery with resection of thymoma. Results: Fever and polyarthritis resolved after operation but recurred in five days due to cytomegalovirus viremia, which might be predisposed by previous antibiotics treatment before the diagnosis of thymoma. Conclusion: Patients with a thymoma also have a high frequency of PNS, and the most frequent condition found in patients with PNS-associated thymoma is myasthenia gravis. Fever with polyarthritis has been rarely reported as a symptom of PNS-associated thymoma. Here we reported an unusual case of PNS mimicking reactive arthritis with thymoma, as diagnosed based on the patient’s clinical progression, imaging examination, and laboratory tests. The patient died of his comorbidities, and his death may have been related to long-term antibiotic use and consequent intestinal dysbiosis. This challenging case may help to inform clinicians of the need for detailed work-up of fever with unknown origin in the presence of chronic polyarthritis to prevent the overdiagnosis of inflammatory arthritis or rheumatic disease and avoid further comorbidities. Detailed work-up should include the patient’s history of infections, inflammation, and malignant or nonmalignant tumors.

Thymic carcinoma presenting with overlap polyarthritis and myositis: A rare paraneoplastic syndrome in childhood

“…8 The true incidence of paraneoplastic syndromes associated with thymic tumors are not known and defined cases are mostly adults rather than children. [1][2][3][4]8,10,11,[21][22][23][24] The World Health Organization histopathological classification and Masaoka-Koga staging systems are the basis of treatment choices in adults and children. 1,25 Thymic carcinoma has the worst outcome and should be considered as an aggressive neoplasm.…”

“…Because of the progression of clinical signs, further investigation revealed a mass lesion in the anterior mediastinum and enlarged lymph nodes, but unfortunately the patient died because of the comorbidities. 8 The true incidence of paraneoplastic syndromes associated with thymic tumors are not known and defined cases are mostly adults rather than children. [1][2][3][4]8,10,11,[21][22][23][24] The World Health Organization histopathological classification and Masaoka-Koga staging systems are the basis of treatment choices in adults and children.…”

“…reported an adult patient with a history of intermittent fever, polyarthritis, and severe myalgia who was initially treated as reactive arthritis. Because of the progression of clinical signs, further investigation revealed a mass lesion in the anterior mediastinum and enlarged lymph nodes, but unfortunately the patient died because of the comorbidities 8 . The true incidence of paraneoplastic syndromes associated with thymic tumors are not known and defined cases are mostly adults rather than children 1–4,8,10,11,21–24 …”

“…In thymic tumors, disturbances in the growth of thymic epithelial cells and thymus structure result in abnormal selection of T cells, leading to autoimmunity and paraneoplastic disorders 7 . Although the association between thymic tumor and arthritis has been reported in adult patients, 8 the association between thymic carcinoma and symmetrical polyarthritis has not been reported in pediatric patients in the current literature. Herein, we present a 15‐year‐old thymic carcinoma case who had systemic symptoms such as fever, fatigue, anorexia, and polyarthritis and accompanying myositis as a paraneoplastic syndrome.…”

Identification of Immune-Related Hub Genes in Thymoma: Defects in CD247 and Characteristics of Paraneoplastic Syndrome

“…The common PNS of thymoma are myasthenia gravis, total red cell aplasia, polymyositis, systemic lupus erythematosus, rheumatoid arthritis, Cushing syndrome, and syndrome of inappropriate antidiuretic hormone secretion ( Rajan and Zhao, 2019 ; Rubinstein et al, 2019 ; Hashimoto et al, 2020 ; Sideris and Huang, 2020 ). A sizeable percentage (25–40%) of thymoma patients with myasthenia gravis, and more than 15% of patients with fever and immunodeficiency such as syndromes ( Zhao et al, 2020 ; Liao et al, 2021 ). Thus, deciphering the relationship between this particular clinical symptom and tumor is crucial for the treatment of thymoma.…”