RECURRENT REARRANGEMENTS OF 11Q14-22 IN MUCOEPIDERMOID CARCINOMA

We describe the cytogenetic findings in five mucoepidermoid carcinomas (MEC) of the major and minor salivary glands. Three of the five tumors analyzed showed an apparently identical t(11;19)(q14-21;p12). In one case, the t(11;19) was the only common clonal abnormality, while in the other two cases the translocation was found together with +16, +20, and inv(1)(p32-33q42), t(6;15)(p12;q25), respectively. The latter case also showed an interstitial short arm deletion of the der(11) chromosome. Of the two remaining cases, one had a del(3)(p13p23) as the sole karyotypic abnormality, while the other had a hyperdiploid stemline characterized by the following numerical deviations: +2, +5, +6, +7, +8, +17, +18, and +19. These findings, together with previously published data from seven MEC, indicate that at least two different, partially overlapping cytogenetic subgroups exist: 1) cases with structural rearrangements of 11q14-22; the finding of three tumors with an apparently identical t(11;19)(q14-21;p12) demonstrates that this is a non-random, and possibly primary abnormality in MEC, and 2) single or multiple trisomies, either observed as the sole anomalies or in combination with structural rearrangements.