Definition: Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Input: Abstract: Clinical and morphologic features of 89 cases of childhood yolk sac tumor (YS) and embryonal carcinoma (EC) (29 associated with teratomas) submitted to the Rare Tumor Registry of the Southwest Oncology Group (1971-1979) or the Pediatric Oncology Group (1980-1984) between 1971 and 1984 were reviewed and submitted to statistical analysis. This review showed an improved survival for each 5-year period regardless of tumor site, no statistically significant difference between "pure" tumors and those mixed with other teratomatous components, no statistically significant difference between YS and EC in children, a better than reported prognosis for sacrococcygeal tumors occurring after the neonatal period, a particularly poor prognosis for neonatal "benign" sacrococcygeal teratomas resected without coccygectomy when they recur as YS, excellent survival for all testicular tumors regardless of age or the presence of EC, and the occurrence of mediastinal tumors in females.

Neoplasms, Embryonal and Mixed