Thymoma with Extensive Necrosis: A Case Report and Literature Review

Thymomas are associated with necrosis and hemorrhage in approximately 5% of cases; however, cases in which necrotic tissue constitutes the majority of tumors are rare.

A 30-year-old man was referred to our hospital with transient anterior chest pain and a mediastinal mass detected on a health check-up. Positron emission tomography/computed tomography showed no fluorodeoxyglucose uptake, and serum and biochemical analyses revealed no elevated inflammatory responses or tumor marker levels. Based on imaging findings, thymic cysts and thymomas were considered differential diagnoses, and thoracoscopic mediastinal tumor resection was performed. The encapsulated tumor, which was adherent to the lung via the thickened pleura, was successfully resected, and a rapid diagnosis of thymoma was made. Final pathological examination confirmed a type B2 thymoma, with necrosis comprising approximately 80% of the tumor. The patient has been followed up on an outpatient basis, with no recurrence at 1 year after surgery.

Extensive necrosis in thymic tumors often suggests high-grade malignancy, but may also occur in necrotic thymoma with a favorable prognosis. Recognizing this possibility is essential to avoid overtreatment and guide appropriate surgical management.