To introduce the application of the foreskin angle and penis-scrotum angle in differential diagnosis of congenitally concealed penis in children.

From September 2016 to September 2020, data from 106 cases of phimosis and 102 cases of congenital concealed penis from Xuzhou Children′s Hospital affiliated to Xuzhou Medical University were compiled. Each age group could be separated into 3 categories: under 6 years old, 6-12 years old, and over 12 years old. Of the phimosis cases, 30 were under the age of six, 45 were between the ages of 6 and 12, and 31 were over the age of 12. In the congenital concealed penis group, 40 cases were under the age of 6, 32 cases were between the ages of 6 and 12, and 30 cases were over the age of 12. The children′s foreskin angle and penis-scrotum angle were both measured and compared.

The foreskin angle was 60.00(45.00, 78.50)° in the congenital concealed penis group and 5.00(0.00, 10.00)° in the phimosis group, respectively, and the difference was statistically significant (Z=12.50, P<0.01). Penis-scrotum angles were 115.00(110.00, 120.00)° and 30.00(0.00, 46.50)° in the two groups, respectively, with a statistically significant difference (Z=12.47, P<0.01). In the congenital concealed penis group, the foreskin angle was 75.50(60.00, 88.75)°, 68.00(50.00, 79.50)°, and 45.00(35.00, 56.25)° in different age groups, with a statistically significant difference (F=25.34, P<0.01). Penis-scrotum angles were 120.00(115.00, 125.75)°, 118.00(110.00, 120.75)°, and 110.00(103.00, 111.00)° in different age groups, respectively, with a statistically significant difference (F=34.32, P<0.01). In the phimosis group, the foreskin angle was 5.00(0.00, 10.00)°, 5.00(0.00, 10.00)°, and 5.00(0.00, 10.00)° in various age groups, with no significant difference (F=0.14, P>0.05). The penis-scrotum angle were 38.50(20.00, 60.00)°, 30.00(0.00, 49.00)° and 20.00(0.00, 40.00)° in different age groups, respectively, and the difference was statistically significant (F=5.00, P<0.01).

Significant difference of the foreskin angle and penis-scrotum angle can be used in the differential diagnosis of concealed penis to help identify the etiology and guide the treatment.