[Primary non-lymphoid thymic neoplasms. A study of 58 cases].

BACKGROUND AND

OBJECTIVE

Primary non-lymphoid thymus tumors (PNLTT) are an uncommon though quite varied pathology. Our objective was to identify the clinical, therapeutic and histologic variables with a prognostic value in these neoplasms.

PATIENTS AND METHOD: We studied 58 PNLTT cases, corresponding to 52 epithelial neoplams (PTEN), 4 thymolipomas (7%) and 2 neuroendocrine tumors (3%). Commonest clinical manifestations were myasthenia gravis (41%) and dyspnea (21%). Three patients were symptom-free (24%). We used Kaplan-Meier survival curves and Cox regression model.

RESULTS

All patients underwent surgery which consisted of thymectomy. Four patients underwent a biopsy procedure alone. Perioperative mortality was 3% (n = 2) and morbidity was 31% (n = 18), mainly because of respiratory and wound problems. 24 patients with PTEN, Masaoka degrees III and IV, and a patient with a lymphoepithelial carcinoma received adjuvant chemotherapy and/or radiotherapy. With a follow-up of 13 + 5 years, 12 PTEN patients and one patient with a neuroendrocrine tumor died as a consequence of the evolution of the disease. Cumulative survival was 80% at 5 years, 71% at 7 years and 63% at 10 years. There are currently two local relapses in two PTEN cases after 9 and 8 years of follow-up, respectively. Main prognostic factors are the histologic type and subtype and the clinical stage (p < 0.001).

CONCLUSIONS

In PNLTT early diagnosis is crucial in order to administer a correct treatment before the clinical stage is more advanced. Main prognostic factors are the histologic type and subtype and the clinical stage.