title: Clinical study on thymoma: assessment of prognostic factors.
abstract: In order to define the clinical features of thymoma, we reviewed 51 thymoma patients in our departments from 1980 to 1995. Of 146 mediastinal tumors, 51 (35%) had thymoma, the most frequent tumor, and 21 (14%) had neurinoma. Twenty-one patients had non-invasive thymoma (Masaoka staging = stage I) and 30 had invasive thymoma (stages II-IV). In the non-invasive group, the male to female ratio was 0.8 (9/12) and the majority were of mixed histologic type (13/21 = 62%). Conversely in the invasive group, the male to female ratio was 1.7 (19/11), and the occurrence of the epithelial type (12 = 40%) was as frequent as the mixed type (13 = 43%). Patients with non-invasive thymoma were all treated with surgery only, and those with invasive thymoma were treated with multimodalities except for one. The 5-year survival rate was 100% for the non-invasive group, and 67% for the invasive group. Patients with accompanying myasthenia gravis (MG) showed a better prognosis than the non-MG patients (P < 0.05). The lymphocytic type also showed a better prognosis than the epithelial type, but this was not statistically significant. The prognosis for patients with thymoma was much better than for those with thymic cancer (n = 9). Thymoma showed a variety of clinical features depending on histologic type and association with myasthenia gravis.
authors.affiliation: First Department of Internal Medicine, Toyama Medical and Pharmaceutical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sassa
authors.forename: Y
authors.initials: Y
authors.lastname: Mizushima
authors.forename: Y
authors.initials: Y
authors.lastname: Kusajima
authors.forename: S
authors.initials: S
authors.lastname: Sugiyama
authors.forename: H
authors.initials: H
authors.lastname: Noto
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013945:Thymoma / Q000453:epidemiology / Q000473:pathology; D013953:Thymus Neoplasms / Q000453:epidemiology / Q000473:pathology