Recurrence of thymoma: analysis of clinicopathologic features, treatment, and outcome

This study reports clinicopathologic features, treatment, and outcome of 30 recurrent thymomas out of 266 totally resected thymomas.

The mean disease-free interval to recurrence was 86 months. Recurrence occurred less frequently and after a longer disease-free interval after resection of encapsulated versus invasive thymomas. The presence of associated myasthenia gravis did not affect recurrence proportion, disease-free interval, or survival after recurrence. A local recurrence occurred in 11 patients, 17 patients had a distant recurrence, and the extent of the recurrence could not be determined in 2 cases. Surgical treatment of the recurrent tumor was attempted in 16 cases, and a total resection was possible in 10 cases; exclusive radiotherapy was done in 11 cases. Overall 5- and 10-year survivals were 48% and 24%, respectively. In a univariate analysis, survival was significantly better in the presence of a local recurrence and in case of a total resection of the recurrent tumor. The use of adjuvant therapy after the resection of the initial thymoma had no effect on reducing the incidence of recurrence, in prolonging the disease-free interval, or in improving survival after the development of the recurrence. In a multivariate survival analysis, significant prognostic factors were the presence of a local recurrence and total resection of the recurrent tumor.

Surgical resection is recommended in patients with recurrent thymoma. Local recurrence and total resection of the recurrent tumor are associated with excellent prognosis. A poor prognosis may be anticipated in the presence of distant recurrence and when radical surgical treatment is not done.