Frequency per year

Average age

Sex

Laterality

Affected side

Matsuda et al. series

22 patients/year

50 years

Female: 60%

Male: 40%

Bilateral: 67%

Unilateral: 33%

Right: 50.2%

Left: 49.8%

Robert and Dennis series

19 patients/year

36 years

Female: 51%

Male: 48%

Bilateral: 68%

Unilateral: 32%

Right: 48.3%

Left: 51.7%

Our series

4 patients/year

22 years

Female: 58.1%

Male: 41.9%

Unilateral: 100%

Right: 75%

Left: 25%