These may be sarcomas or carcinomas. However, marked atypia of epithelial or stromal cells post-chemotherapy is not diagnosed as malignant unless invasion or large areas of atypical cells are present. Metastases often show a pattern of mature teratoma even though the primary is predominantly of another type. Some metastases with cartilage and epithelium can resemble benign hamartomas of the lung. If metastases contain only mature tissues or necrotic tumor, no further therapy is required.
Prognosis is good.
Chapter 18, Male reproductive system. 8th ed., Chicago,Mosby Co. 1996, 1265-1295. Roth L. A pathologic analysis of lesions following modern chemotherapy for metastatic germ-cell tumors. Debono D, Heilman D, Einhorn L, Donohue J. Decision analysis for avoiding postchemotherapy surgery in patients with disseminated nonseminomatous germ cell tumors. The development of non-germ cell malignancies within germ cell tumors.