ABERRATIONS OF CHROMOSOME SEGMENT 12Q13-15 CHARACTERIZE A SUBGROUP OFHEMANGIOPERICYTOMAS

Background. In later years, several characteristic acquired chromosoma l aberrations have been identified in mesenchymal tumors. Many of thes e aberrations, either alone or with histopathologic and clinical data, are useful in diagnosis. The cytogenetic profile of hemangiopericytom as has been poorly investigated.Methods. Short-term cultures from four spindle cell tumors were cytogenetically analyzed. Results. Clonal ac quired chromosome aberrations were found in three of the four tumors: inv(12) (q14q24) in a malignant hemangiopericytoma, a supernumerary de r(3)t(3;12) (p21-23;q13-15) in a benign hemangiopericytoma, and t(6;12 ;19) (p21;q13;p13) in a spindle cell sarcoma that was histologically a malignant hemangiopericytoma or a synovial sarcoma. The fourth tumor, a malignant hemangiopericytoma, had a normal karyotype. The tumors wi th inv(12) and t(6;12;19) had subclones with trisomy 5 in addition to the structural changes. Conclusions. The current findings and the lite rature data indicate that a subgroup of hemangiopericytomas is charact erized by rearrangement of chromosome segment 12q13-15.