Cytogenetic, ras, and p53: Studies in cases of canine neoplasms (hemangiopericytoma, mastocytoma, histiocytoma, chloroma)

Four case reports of mesenchymal neoplasms showing chromosomal abnormalitie s are presented, In a case of hemangiopericytoma trisomy 2 and centric fusi on 19;21 were present. In a mastocytoma a deleted chromosome 35 was seen, A homogeneously staining region (HSR) on chromosome 1 was detected in a hist iocytoma, Trisomy 5 and monosomy 31 were observed in a case of granulocytic sarcoma (chloroma). The lack of mutations in exons 1 and 2 of oncogenes N- ras, Kras, and H-ras and exons 5, 6, 7, and 8 of tumor suppressor gene p53 in these four patients and in a larger series of investigated dogs (25 hema ngiopericytomas, 12 mastocytomas, and 8 histiocytomas) is highlighted.