Gains of chromosomes 7 and 17 in tubulocystic carcinoma of kidney: two cases with fluorescence in situ hybridisation analysis.

Tubulocystic carcinoma (TCC) is a very rare renal tumour with unique gross and microscopic features, alternatively considered as low-grade collecting duct carcinoma. Recent studies favoured distinction of TCC from collecting duct carcinoma, and some cases of TCC synchronously coexisting with other renal cell tumour subtypes were described. We report here two new cases of pure (case 1) or mixed (case 2) TCC with fluorescence in situ hybridisation (FISH) analysis, which showed gains of chromosomes 7 and 17 in the pure TCC of case 1, as well as in the TCC and the papillary renal cell carcinoma (PRCC) components in case 2. These data may further support the notion that TCC is more closely related to PRCC. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.