Thymic carcinoma with dissemination: a retrospective analysis of ten patients

Thymic carcinoma is a rare mediastinal neoplasm with frequent pleural or pericardial dissemination. We retrospectively studied ten such cases and analyzed factors that influenced the survival of the patients.

Ten thymic carcinoma patients with dissemination have been treated since 1987. The clinical and pathological data were retrospectively reviewed.

Pretreatment tumor biopsy was performed and demonstrated squamous cell carcinomas in nine and small cell carcinoma in one. In six of ten patients pleural or pericardial dissemination was clinically evident (cT4). These patients were basically regarded as inoperable and treated with chemotherapy and/or radiotherapy. Four other patients were diagnosed as cT3 preoperatively but were found to have dissemination at the time of thoracotomy. They underwent total resection of the thymic tumor and all visible pleural dissemination but without pericardial dissemination. Radiotherapy was performed pre-or postoperatively with or without chemotherapy. The 5-year survival rate in all patients was 42.0%. The patients with Masaoka stage IVa showed significantly better prognosis than the patients with stage IVb (MST, 69.7 months vs. 14.5 months; 5-year survival rate, 64.3% vs. 0%) (P = 0.03). The patients with cT3 disease showed significantly better prognosis (P = 0.016) than the patients with cT4 disease (MST, 69.7 months vs. 14.5 months; 5-year survival rate, 100% vs. 16.7%).

Among thymic carcinoma patients with pleural or pericardial dissemination, there seem to be some patients who show good prognosis. These candidates are patients who underwent subtotal resection with disseminations that were identified only at the operation and without hematogenous or lymphogenous metastasis.