Primary mediastinal malignancies: Findings in 219 patients

The purpose of this study was to determine the demographics, histology, met hods of treatment, and survival in primary mediastinal malignancies. We did a retrospective review of the statewide New Mexico Tumor Registry for all malignant tumors treated between January 1, 1973 and December 31, 1995. Ben ign tumors and cysts of the mediastinum were excluded. Two hundred nineteen patients were identified from a total of 110,284 patients with primary mal ignancies: 55% of tumors were lymphomas, 16% malignant germ cell tumors, 14 % malignant thymomas, 5% sarcomas, 3% malignant neurogenic tumors, and 7% o ther tumors. There were significant differences in gender between histologi es (P < 0.001). Ninety-four percent of germ cell tumors occurred in males, 66% of neurogenic tumors were in females; other tumors occurred in males in 58% of cases. There were also significant differences in ages by histology (P < 0.001). Neurogenic tumors were most common in the first decade, lymph omas and germ cell tumors in the second to fourth decades, and lymphomas an d thymomas in patients in their fifth decades and beyond. Stage at presenta tion (P = 0.001) and treatment (P < 0.001) also differed significantly betw een histologic groups. Five-year survival was 54% for lymphomas, 51% for ma lignant germ cell tumors, 49% for malignant thymomas, 33% for sarcomas, 56% for neurogenic tumors, and 51% overall. These survival rates were not stat istically different (P > 0.50). Lymphomas, malignant germ cell tumors, and thymomas were the most frequently encountered malignant primary mediastinal neoplasms in this contemporary series of patients. Demographics, stage at presentation, and treatment modality varied significantly by histology. Des pite these differences, overall five-year survival was not statistically di fferent.