A 7-Month-Old Boy Is Brought to the Office for a Routine

A 7-month-old boy is brought to the office for a routine visit.  The parents' only concern is that their son's "private area looks abnormal," which his primary care provider has been monitoring.  He breastfeeds on demand and recently started eating pureed fruits and vegetables.  The infant urinates frequently and stools once a day.  He rolls in both directions, responds to his name, and transfers objects from one hand to the other.  The patient was born by cesarean delivery at 36 weeks gestation for maternal preeclampsia.  He was small for gestational age but has gained weight appropriately since birth.  Weight, length, and head circumference track along the 30th percentile.  Physical examination shows an interactive and alert infant.  The abdomen is soft, nontender, and nondistended.  Genital examination reveals a hypoplastic, hypopigmented, empty left scrotum (shown in the image below) . A small mobile mass is palpable in the left inguinal canal.  The right testicle is palpated in the right hemiscrotum, which has normal cremasteric reflex and normal rugae.  The penis is uncircumcised, and the urethral meatus is at the tip of the glans.  Which of the following is the most appropriate next step in management of this patient?

A) Order a karyotype analysis
B) Order an abdominal ultrasound
C) Reassure and continue observation
D) Schedule the patient for an orchiopexy
E) Surgically excise the mass