An epidemiological study of renal pathology in tuberous sclerosis complex

To report the frequency of renal symptoms and complications of patients with tuberous sclerosis complex (TSC), to describe the ultrasonographic appearance of the kidneys in a population-based sample, and to investigate the relationship between a history of renal haemorrhage and renal lesions identified by ultrasonography.

As part of an epidemiological study, 179 patients with TSC were identified as living in the Wessex Region in the South of England. Patients were interviewed and examined in their homes, to elicit the presence of renal symptoms or a history of renal complications. Renal ultrasonography was used in consenting patients in their homes.

There was a history of renal complications in 16 (9%) patients; 149 consented to interview and examination, and 19 gave a history of renal symptoms in the previous year; 124 had renal ultrasonography; 86 (69%) had renal angiomyolipomas and 37 (30%) had renal cysts. Large lesions (>3 cm in diameter) were strongly associated with a history of symptomatic bleeding, although significant haemorrhage occurred in a 6-year-old child with small angiomyolipomas.

The formation of angiomyolipoma in TSC is common. Polycystic kidney disease, renal carcinoma and renal failure, although rare, occur in TSC. Most patients with angiomyolipomas have neither complications nor symptoms. There was no appreciable difference between the sexes in the risk of developing these lesions. Although less commonly seen in the very young, there is no identifiable relationship after adolescence between age and the risk of having a renal angiomyolipoma. Bleeding tends to occur from large lesions (>3 cm) but most such patients have remained asymptomatic to date.