[Tumor size and DNA ploidy changes in renal cell carcinomas--flow cytometric analysis of DNA content in renal cell carcinomas associated with von Hippel-Lindau disease].

ABSTRACT

BACKGROUND: Renal cell carcinomas (RCCs) develop in 8-63% of von Hippel-Lindau disease (VHL) patients, and loss of 3p segments, chromosome aberrations found in 90% of sporadic RCCs, has also been observed in RCCs associated with VHL. In fact, comparative analysis showed that the chromosome aberrations in RCCs associated with VHL are similar to those found in sporadic RCCs. VHL patients have the whole spectrum of tumors from small early lesions to large ones in the same kidney, providing a unique opportunity to analyze tumors in different stages of development. Subsequently deoxyribonucleic acid (DNA) content in RCCs of VHL patients was examined and correlated to their tumor size to gain some insight in the progression of sporadic RCCs. METHODS: From 1988 to 1991, we have experienced 6 cases of RCCs associated with VHL who underwent partial or radical nephrectomy. A total number of 52 paraffin-embedded samples from 33 RCCs from 6 patients with VHL was analyzed by flow cytometry. RESULTS: The sizes of tumors ranged from 0.2 to 8.2 cm. DNA aneuploid patterns demonstrated in none of 9 tumors less than 1.6 cm, 4 of 14 tumors (29%) as large as 1.6 to 2.5 cm, and 5 of 10 tumors (50%) larger than 2.5 cm (p < 0.05). Twelve tumors less than 1.8 cm showed DNA diploid, so the smallest size of aneuploid tumors was 1.8 cm. CONCLUSION: These data suggest that DNA ploidy change (diploid to aneuploid) in RCCs probably takes place as tumors grow approximately 1.8 cm in size.