First cytogenetic study of a recurrent familial chordoma of the clivus

Two recurrences of a familial clivus chordoma, arisen from a patient who de veloped the primary tumor at age of 8 years, were investigated by cytogenet ic and the fluorescence in situ hybridization (FISH) approach. Of the patie nt's 3 daughters, 2 developed, respectively, a clivus chordoma and an astro cytoma in infancy, a familial aggregation highly suggestive of a genetic ba ckground. After a 31-year hiatus, 2 tumor recurrences, developed over 17 mo nths, were removed surgically, Both were hypo- or nearly diploid, and had a pronounced karyotypic heterogeneity with clonal and non-clonal rearangemen ts affecting several chromosomes. The same rearrangement; a dic(I;9)(p36.1; p2I), was shared in both tumor specimens and, in 90% of the cells, chromoso me Ip appeared to be involved in unbalanced translocations with different c hromosomes, leading to variable losses of Ip. Previous. cytogenetic data co ncerning chordoma are limited to 10 tumor-specific rearrangements have been identified, chromosome Ip appears to be involved frequently. (C) 1999 Wile y-Liss, Inc.