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Malignant triton tumors (MTT) are rare soft-tissue tumors characterized by a mixture of cells with nerve sheath and skeletal muscle differentiation. MTT is a histological variant of malignant peripheral nerve sheath tumors (MPNST). No characteristic cytogenetic anomaly has been detected in MPNST or MTT. In this paper, we report on the cytogenetic findings of an MTT from a 20-year old male with neurofibromatosis (NF1). The tumoral karyotype showed the modal number to be near-diploid and an abnormal karyotype with a Robertsonian translocation and 4 markers: 49,XY,der(14;15)(q10;q10),+4mar. Spectral karyotyping revealed the karyotype: 49,XY, der(14;15)(q10;q10),+i(8)(q10)×4. Fluorescence in situ hybridization analysis of the tissue confirmed the presence of the additional i(8)(q10) in all tumoral cells. The sequence analysis of p53 revealed a polymorphism in exon 9, codon 329. The two alleles, TTC and TCC, codify for phenylalanine and serine, respectively. Our results indicate that all neoplastic cells have the same cytogenetic pattern, suggesting that both cell lines, which show nerve sheath and skeletal muscle differentiation, are derived from a unique stem cell. The acquired Robertsonian chromosomal recombinants might represent an event in the tumorigenesis of MTT, and the present data suggest that genes located on 8q can be involved in the development of MTT. [Copyright &y& Elsevier]

Abstract: We describe the case of a boy with psychomotor delay and dysmorphic features, with a germline 16q22.1 microdeletion identified by array-CGH. The deletion spans 0.24Mb and encompasses three genes (ZFP90, CDH3 and CDH1). The deletion has been demonstrated to be inherited from his mother who was affected by lobular breast cancer (LBC) without any other apparently phenotypic features. We suppose that the microdeletion, in particular ZFP90 which is cerebrally expressed, is causative for the boy''s phenotype. Mental retardation in the affected boy can recognize several mechanisms such as variable expressivity, non-penetrance, multifactorial/polygenic inheritance, recessive inheritance, a second rearrangement event and epigenetics. Furthermore, we suggest that the deletion of the CDH1, a tumor suppressor gene, involved in hereditary diffuse gastric cancer (HDGC) and LBC predisposed the mother to the carcinoma. [Copyright &y& Elsevier]