Malignant mesenchymoma and birth defects. Prenatal exposure to phenytoin.

Malignant mesenchymoma developed in an 18-year-old patient with phenytoin-associated cleft lip and palate. Although these conditions may be related by chance, the possibility of transplacental carcinogenesis by phenytoin should be considered, especially since neuroblastoma was reported recently in two children with phenytoin-induced malformations. Following combination chemotherapy for metastases, the patient experienced a 7-year disease-free interval, which is consistent with recent improvement in the treatment of soft-tissue sarcomas.