Thymic epithelial neoplasia: a study of 58 cases

Abstract

Primary thymic epithelial neoplasms (PTENs) are uncommon tumors of anterior mediastinum with a broad range of biological characteristics. We retrospectively reviewed 58 consecutive patients with a diagnosis of PTENs that were confirmed pathologically during 28 yr. There were 58 patients, 31 males (53.4%) and 27 females (46.6%), with a mean age of 43.6 +/-13.8 yr (range, 17-73 yr). Twenty-one (36.2%) patients presented at the Masaoka stage I, 13 (22.4%) patient at stage II, 18 (31.0%) patient at stage III, and 6 (10.4%) patients at stage IV. Forty-five (77.7%) patients had myasthenia gravis, 1 (1.7%) immune deficiency, 1 (1.7%) pancytopenia, and 1 (1.7%) nephrotic syndrome. No paraneoplastic syndrome was associated in 10 (17.2%) patients. Complete resection was accomplished in 41 (70.7%) patients, while incomplete resection was performed in 8 (13.8%) patients. In nine (15.5%) patients only biopsy was carried out. Radiotherapy was administered to 19 (32.8%) patients. Eleven (19.0%) out of 58 who presented at advanced stages (at least III) received chemotherapy. Median follow-up period was 59 mo (range, 1-278 mo). During the follow-up period, 17 deaths occurred. Five patients (29.4%) died of tumor-related causes, and the remaining 12 patients died of other causes (cardiovascular diseases [n = 1, 5.9%], sepsis [n = 4, 23.5%], and MG-related respiratory insufficiency [n = 7, 41.2%]). The overall survival rates at 5 yr and 10 yr were 63.9% and 54.2%, respectively. Tumor-related survival rates at 5 yr and 10 yr were 89.0% and 83.2%, respectively. In our series, disease stage, presence or absence of myasthenia gravis, and tumor size did not affect survival (p> 0.05), either. Complete resection of the tumor seems to be the best predictive factor for long-term survival.