[Precancerous lesions of the urothelium. From Feulgen staining to single cell CGH]. / Präkanzerosen des Urothels. Von der Feulgen-Färbung bis zur Einzelzell-CGH.

Feulgen staining represents a staining method to quantitatively document the DNA content of a nucleus. Thus it is an excellent and straightforward method to reflect the irregular increase in DNA content of a malignant cell as a sign of genetic instability. Genetic instability of the tumour cell is the key feature of the 2004 WHO classification of bladder tumours, in which flat and papillary neoplasia are grouped into low- and high-grade lesions. "High grade" represents the tumor with genetic instability and consequently a higher likelihood of progression. Concomitant distinct genetic aberrations other than the numeric ones are increasingly identified as discriminators and help group the entities. The current status of genetic investigations, especially those in precancerous lesions, will be outlined in this review in the context of morphology (histology and cytology) as well as clinical situation.

[Nested-variant urothelial carcinoma. Case report and molecular aspects]. / Die Nested-Variante des Urothelkarzinoms. Fallbericht und molekulare Aspekte.

The nested variant of urothelial carcinoma is a rare urothelial neoplasia which is characterized by relatively bland morphology and early muscle-invasive growth. We report on a 65-year-old male patient with a non-invasive high-grade urothelial lesion (carcinoma in situ and pTa G3). After treatment with BCG an invasive urothelial carcinoma was discovered whereas the carcinoma in situ had disappeared. Examination of the bladder specimen showed a nested-variant urothelial carcinoma. Molecular analyses indicated a de-novo genesis of the invasive urothelial carcinoma.