Objectives  To assess the incidence, clinicopathological features, prognosis and therapeutic options of cystic renal cell carcinoma (CRCC). Patients and methods  The clinical records and nephrectomy specimens from 206 patients with renal cell carcinoma (RCC) were reviewed after a minimum follow‐up of 5 years. The mode of presentation, tumour size, growth pattern, nuclear grade, cytoplasmic appearance and pathological stage at presentation were compared with the outcome, as measured by disease‐free and overall survival of the patients. Results  From the 206 patients with RCC, 25 (12%) were classified as having CRCC; most of these cases (96%) occurred in male patients, as opposed to 64% in the remaining patients RCC (P=0.0029). The clinical features at diagnosis were similar in both groups, although asthenia, anorexia and weight loss were uncommon in patients with CRCC (P=0.045). Nuclear grade and pathological stage were usually lower in those with CRCC than in those with RCC (P=0.0071 and P=0.0033, respectively). Survival was significantly longer in patients with CRCC (P=0.0342). Conclusions  CRCC is a type of RCC that is usually identified at earlier stages, has a slower growth rate, and is therefore associated with a better prognosis and longer survival than conventional RCC. The differential diagnosis between CRCC, cystic multilocular nephroma and cysts with a superimposed infectious or haemorrhagic process can be extremely difficult in imaging studies, and even in intra‐operative frozen‐section analysis. Because of this, and with the better prognosis of CRCC, a conservative surgical approach would be the treatment of choice whenever technically feasible.

Case reporttwo areas of cancer biology. First, the generation of a cancer cell is a multi-step process, requiring the acti-A 74-year-old man had undergone radical cystectomy in September 1992 for a high-grade, invasive and mul-vation of dominant-acting oncogenes, inactivation of tumour suppressor genes and the acquisition of immor-tiple TCC of the urinary bladder (G2/pT2) and had an ileal neobladder constructed. He was a heavy smoker tality. The presence of genetic instability does not necessarily mean that a cell will generate these events, but it (600 packs per year) and had previously been healthy. There was no family history of malignancy. A cytogen-may increase the probability. Second, an important manifestation of genetic instability and tumour cell etic study of the tumour cells in culture showed many structural and numeric non-clonal abnormalities.heterogeneity is the development of variant cells within the cancer population. This results in the generation of Furthermore, a cytogenetic study of lymphocytes showed no clonal disturbances, but structural abnormalities in cells that are drug-resistant, have altered antigenicity and show increased metastatic potential. Therefore, 13% of the metaphase stages and 3.5% with chromosomal weakness, both values being greater than normal.accepting chromosomal instability as a factor that increases the risk of neoplasia, such patients must be Because of the chromosomal abnormalities the patient was followed closely; a year later he presented with followed closely to detect recurrence or new cancers at an early stage. melanoma and was diagnosed with a second epithelial cancer in the sigmoid colon. An anterior resection was performed, the pathological staging being pT3N0M0. One year later, having remained free of symptoms, Referencesthe patient presented with epigastric pain, nausea and 1 Heims S, Johansson B, Mertens F. Constitutional chromosome vomiting. Gastroscopy revealed a third epithelial maliginstability and cancer risk. Mut Res 1989; 221: 39-51 nancy in the gastric antrum. Laparotomy showed dis-2 Brown T, Dawson AA, McDonald IA, Bullock I, Watt JI. Chromosome damage and sister chromatid exchanges in semination of the cancer involving the peritoneum. lymphocyte cultures from patients with two primary cancers.