Ineke Molenaar

Karyotyping and DNA flow cytometry of mature residual teratoma after intensive chemotherapy of disseminated nonseminomatous germ cell tumor of the testis: a report of two cases

Karyotyping and DNA flow cytometry was performed on mature residual teratoma cells following intensive chemotherapy of disseminated nonseminomatous germ cell tumor of the testis to study its biology. We report herein a successful method for short-term tissue culture and karyotyping of retroperitoneal residual mature teratoma in two cases. In vitro morphology confirmed that the cultured cells were nonembryonal carcinoma cells. Both mature residual teratomas were highly aneuploid and possessed the i(12p) marker characteristic of testicular germ cell tumors. A clone in the retroperitoneal residual lesion of one of the patients showed a DNA-index different from the primary tumor and might represent a clone unmasked by chemotherapy. In view of these data, which are in agreement with recent reports on secondary non-germ cell malignancies arising in mature residual teratoma, aggressive surgery of mature residual lesions seems justified.

Frequent loss of 9p21 (p16(INK4A)) and other genomic imbalances in human malignant fibrous histiocytoma

To search for new recurrent genetic aberrations in malignant fibrous histiocytoma (MFH), a combination of conventional cytogenetic, comparative genomic hybridization (CGH), and Southern blot analyses was applied to a series of 34 tumors. Cytogenetic analysis revealed the presence of multiple structural and numerical aberrations, including marker chromosomes, telomeric associations, double minutes, and ring chromosomes. The most frequent genomic imbalances in this series of neoplasms as detected by CGH were gains of 1q21-q22 (69%), 17q23-qter (41%), and 20q (66%), and losses of 9p21-pter (55%), 10q (48%), 11q23-qter (55%), and 13q10-q31 (55%). Southern blot analyses with p16(INK4A) (CDKN2A; 9p21) and RB1 (13q14) probes provided clear indications for frequent deletions of these tumor suppressor genes, and as such, substantiated the CGH results. Additionally, examination of the TP53 and MDM2 genes showed frequent loss and amplification, respectively. These data indicate that genes involved in the RB1- and TP53-associated cell cycle regulatory pathways may play prominent roles in the development of human MFH.

Malignant hemangiopericytoma in three kindred members of one family

Three cases of malignant hemangiopericytoma in one family are reported. To our knowledge familial occurrence of malignant hemangiopericytoma has not been described before. Two of these lesions occurred in the head and neck region and one case presented as an intraabdominal tumor. Consanguinity of the parents seems to be likely, suggesting an autosomal recessive mode of inheritance in our family, whereas the similarity in age of onset in these three patients was apparent.