HIBERNOMAS ARE CHARACTERIZED BY REARRANGEMENTS OF CHROMOSOME BANDS 11Q13-21

Cytogenetic analysis revealed structural rearrangements of 11q13-21 in 9 lipogenic tumors-4 hibernomas, 4 typical lipomas and 1 mixed myxoid and well-differentiated liposarcoma. Two hibernomas and all lipomas s imultaneously showed aberrations attributable to previously recognized cytogenetic subgroups among benign adipose tissues tumors, i.e., supe rnumerary ring chromosomes or rearrangements of 6p, 12q13-15, or 13q. The sole anomaly in the liposarcoma was a 4-way translocation t(9;11;2 2;12)(q21;q13;q11;q13), an aberration that has not previously been det ected in either myxoid or well-differentiated liposarcomas. Together w ith our 4 cases, a total of 7 cytogenetically aberrant hibernomas have been reported. Five tumors have shown rearrangements of 11q13 and 2 o f 11q21, indicating that this segment of chromosome 11 harbors one or more genes of importance in hibernoma development. Rearrangements of 1 1q13-21 also appear to be frequent in typical lipomas; a total of 8 ty pical lipomas with 11q13-21 changes have been described, including tho se in our series. In all but 1, however, breakpoints were also found i n 6p, 12q13-15, or 13q. (C) 1994 Wiley-Liss, Inc.