Pseudodicentric (16;12)(q11;p11.2) in a type AB (mixed) thymoma

Genetic alterations of thymomas are rarely described in the literature. In this study, a previously unreported instance of aberrant karyotypic change consisting of 45,XX,pseu dic(16;12) (q11;p11.2) [cp23]/87-90,idemx2[cp4] in a Masaoka Stage II mixed thymoma or type AB thymoma affecting a 56-year-ol d Chinese woman is detailed. Abnormalities involving 12p containing importa nt tumor suppressor-like genes have been documented especially in hematolog ical malignancies. Recently, recurrent losses involving 16q, a locus known to harbor several tumor suppressor genes, have been described in type C thy momas (squamous cell carcinoma), suggesting a possible relationship between type AB thymoma and type C thymoma. Whether these genes are involved in th e pathogenesis of type AB thymoma remain to be clarified and it is currentl y unclear if cytogenetic studies may eventually play a role in the classifi cation of thymic tumors. (C) 2001 Elsevier Science Inc. All rights reserved .