Is the incidence of urinary bladder endometriosis increasing? Figures from Finland

Urinary bladder endometriosis is a severe form of endometriosis often requiring surgery. The several cases treated at our hospital in recent years has led us to evaluate the incidence of urinary bladder endometriosis in Finland.

We performed a register-based analysis of incidence of urinary bladder endometriosis. The patients were identified according to registered diagnosis and operation codes.

Six urinary bladder endometriosis cases were diagnosed at Oulu University Hospital during 1991-2007. These cases have been presented. The annual incidence, as evaluated from The Finnish Care Register HILMO, increased from 3.6 to 9.4 cases/1,000,000 females aged 15-49 years per year during 1996-1999 and 2004-2007, respectively, in Finland.

There is an apparent increase in incidence of urinary bladder endometriosis in Finland. The low number of cases detected at Oulu University Hospital, and the limitations of the incidence evaluation based on the HILMO register, exclude the presentation of an accurate incidence. The results presented warrant further and careful evaluation of potential increases in urinary bladder endometriosis elsewhere.