There is no benign or malignant statement for thymoma, it can be divided into 4 stages according to the presence or absence of tumor envelope invasion, metastasis, etc., and the recurrence rate is different according to different stages.
Currently there is no benign or malignant statement for thymoma. Thymoma can be divided into 4 stages according to Masaoka-Koga staging, i.e., stage 1 is thymoma with peritumor, stage 2a is microscopic peritumor invasion, stage 2b is adjacent fat invasion visible to the naked eye, stage 3 is adjacent structures/organs invasion, stage 4a is pleural/pericardial involvement, and stage 4b is lymphatic/bloodstream metastasis.
Thymoma recurrence is related to the presence or absence of peritoneum, organ damage, and metastasis, etc. Stage 1 with peritoneum and no adhesion to surrounding organs usually does not recur after surgery.Stage 2 with tumor invasion and complete resection of the tumor may recur and metastasize after surgery.Stages 3 and 4 generally have a high rate of postoperative recurrence.
Therefore, the diagnosis of thymoma should be treated early to avoid adverse consequences.