Repeated USMLE Questions Step 1 - 156

A 9 month-old boy is brought to the clinic by his mother who is concerned that the boy developed swelling in his right scrotum. On examination, there is a scrotal mass that disappears when pushing it back to the external inguinal ring. When the boy cries, the mass is felt again protruding out of the external inguinal ring.

What is the most likely etiology of this condition?

A-Defect in the inguinal canal
B-Defect in the pelvic floor
C-Patent processus vaginalis
D-Defective closure of tunica vaginalis
E-Undescended testis






Answer:

The most important cause of inguinal hernia in infants is patent processus vaginalis which fails to be obliterated after descending of testes. Persistent lumen of tunica vaginalis causes hydrocele, not hernias.

The correct answer is C