Trisomy 7 may be a primary change in noninvasive transitional cell carcinoma of the bladder

We describe two cases of transitional cell carcinoma of the bladder associated with trisomy 7. In one of them, trisomy 7 was the only chromosome abnormality observed. In the second case, trisomy 7 was found in 25 (80.6%) of the metaphases; in two of them this was the only anomaly, while in three metaphases trisomy 8 was also present, and in other two trisomy 10 was also observed. Our results suggest that trisomy 7 could be a primary change in TCC, and a review of the literature indicates that when it is present as the sole karyotypic abnormality is may be associated with a non-invasive behavior of the tumor.