Cytogenetic analysis of an immature teratoma of the ovary and its metastasis after chemotherapy-induced maturation.

We report a case of an immature teratoma of the ovary, grade 3, in which cytogenetic studies were performed on the primary tumor at diagnosis and on a metastasis resected 1 year after removal of the primary tumor. The patient was treated with cisplatin, bleomycin, and etoposide (VP-16) combination chemotherapy. The metastatic tumor was composed of mature teratoma with only small foci of immature tissue. Despite the different histologic appearance of the primary tumor and the metastasis, there was no detectable difference in karyotype between the primary and metastatic tumors. Both showed a pseudodicentric chromosome derived from chromosome 1 and monosomy for chromosome 4. Flow cytometry analysis of the metastatic tumor showed a diploid DNA content, in agreement with the cytogenetic findings. From this case it would appear that chemotherapy-induced maturation of metastatic immature ovarian teratoma is not associated with regression of the malignant karyotype or selection of a karyotypically distinct population of tumor cells.