Inguinal Lumps and Bumps
Sara T. Stewart, MD, MPH, FAAP
A 2-month-old boy presents to your office for evaluation of a lump that has been evident in his right groin for the past week. The lump has been coming and going, and his mother notices that it is larger when he cries. Today, the lump is prominent, and the infant seems fussy. He has been crying more often than usual and vomited once today. His history is remarkable for having been born at 32 weeks of gestation by spontaneous vaginal delivery. Birth weight was 1,500 g (3.3 lb), and he did well in the nursery, with no respiratory complications. He was sent home at 4 weeks of age and has had no other medical problems. He breastfeeds well and has normal stools.
Physical examination reveals a well-nourished, irritable infant in no acute distress. His vital signs demonstrate mild tachycardia and a temperature of 37.8°C (100°F). His abdomen is soft, and the genitourinary examination is significant for a swelling in the right inguinal area that extends into his scrotum. The mass is mildly tender and cannot be reduced. The remainder of the examination is normal.
1. What are the possible causes of an inguinal mass?
2. How does age affect the diagnostic possibilities?
3. How does the physician differentiate between acute and nonacute conditions?
4. What diagnostic modalities can help with the diagnosis?
5. What are the treatment options for inguinal masses?
6. What, if any, are the long-term consequences of inguinal masses?
Inguinal masses arise from disease in normal tissue in the inguinal area or from ectopic tissue, frequently of embryologic origin. A child may present with the chief report of an inguinal mass, and the mass may be located anywhere along the inguinal canal to the scrotum or labia (Figure 108.1). Along the inguinal canal, a mass might be an enlarged lymph node, a retractile testis, an ovary, or a synovial cyst. At the inguinal ring, a mass might also be a testis or an ovary, or an inguinal hernia. In the scrotum, swelling can result from hernia, hydrocele, varicocele, trauma, or testicular pathology. The labial lesion can be secondary to trauma; an ectopic ovary; mixed gonadal tissue; an actual testis, as in testicular feminization; or a Bartholin cyst. The differential diagnosis and subsequent evaluation vary based on the location of the mass, patient age, and the acuity of presentation of the mass.
Figure 108.1. The inguinal area of a male individual.
Inguinal masses are a fairly frequent finding reported in the office setting. The usual cause is an enlarged lymph node, but hernias and hydroceles are also common. The most common surgical procedures performed in children are to repair hernias and hydroceles. The prevalence of inguinal hernias has been estimated to be 1 to 4 per 100 live births. There is a 60% risk of incarceration in the first 6 months after birth if the hernia is left untreated. For this reason, surgical correction is recommended early. Hernias are present on the right side in 60% of cases, are present on the left side in 30%, and are bilateral in 10%. Of affected children, males outnumber females 4:1. Femoral and direct hernias are more common in girls. Certain conditions are associated with an increased incidence of hernias (Box 108.1). The most significant predisposing factor is preterm birth, with hernias reported in 30% of newborns weighing less than 1,000 g (<2.2 lb) at birth.
For the other common acute scrotal lesions, 1 out of 160 males experience either testicular torsion or torsion of the appendix testis. Testicular torsion may occur in utero, but the peak incidence of testicular torsion occurs in the perinatal period and again at puberty. Torsion of the appendix testis is most likely to occur between ages 7 and 10 years. Varicoceles occur in pubertal and postpubertal males, with a fairly high rate of up to 15%. Testicular tumors are rare in childhood, occurring in 0.5 to 2.0 per 100,000 children and accounting for only 1% of all pediatric solid tumors. In adolescence, however, testicular cancer is the most common cause of cancer in young males and may affect as many as 1 in 10,000.
Box 108.1. Conditions Associated With Increased Risk for Hernia in the Neonate
•Abdominal wall defect
•Connective tissue disease
•Low birth weight
The child with an inguinal mass presents acutely or nonacutely. In the acute presentation, the swelling occurs rapidly and is associated with pain. The associated systemic symptoms of nausea and vomiting may occur. Inguinal pathology should be suspected in any child with abdominal pain. The involved area may be extremely tender. Nonacute masses appear more slowly. Some may be present from birth. They may come and go, especially with crying or straining. Nonacute masses usually are not tender and are not associated with systemic symptoms (Box 108.2).
Box 108.2. Diagnosis of Inguinal Masses
•Nausea and vomiting
•Overlying skin red
•Cremasteric reflex absent
•May fluctuate in size
•Cremasteric reflex present
Pathophysiological developmental features of an inguinal mass vary depending on the cause of the mass. An enlarged lymph node may result from proliferation of intrinsic lymphocytes or inflammatory infiltrate from infection (eg, lymphadenitis). The etiology of lymphadenopathy is extensive (see Chapter 100). Any of these processes can occur in the inguinal nodes. An enlarged node also can be secondary to metastatic infiltration from another cell line and can represent tumor spread.
A hydrocele develops secondary to failure of obliteration of the patent processus vaginalis during embryologic development. During the 27th to 28th weeks of gestation, the testicle, gubernaculum, and processus vaginalis descend from the peritoneum through the inguinal canal into the scrotum. The processus vaginalis begins closing before birth and attaches to the testis, forming the tunica vaginalis testis. The closure is complete by 1 to 2 years of age. Failure of closure results in a hydrocele if the processus vaginalis fills with fluid and results in a hernia if intra-abdominal contents intermittently descend through the processus vaginalis. Either of these may bulge into the inguinal canal and scrotum. The incarcerated hernia is one that cannot be reduced and that places abdominal contents at risk for vascular compromise. This condition is a surgical emergency.
Sometimes a parent or guardian may misinterpret a normal testicle in the process of descent as an abnormal mass. A delay in the normal descent process of the testis occurs occasionally, and the testicle may not be in the scrotum at the time of birth. Torsion of the testis after it has reached the scrotum can occur in the newborn if the testis twists on the spermatic cord. Similarly, the testicle also can twist in the pubertal period on its own vasculature within the tunica vaginalis. This frequently occurs secondary to a high attachment of the tunica vaginalis to the spermatic cord, allowing the testis to hang freely, like a bell clapper. Both types of torsion cause vasculature compromise and an ischemic testis, and both types are surgical emergencies.
Likewise, a vestigial remnant called the “appendix testis” can twist, resulting in vascular compromise of that localized part of the testis.
Pathologically, a traumatic scrotal mass is usually a hematoma, although testicular rupture may occur if the tunica albuginea of testis is torn as a result of trauma. Testicular neoplasms in prepubertal children tend to be germ cell tumors. Yolk sac tumors, teratomas, and mixed germ cell tumors with infiltration of their respective cell lines are the usual diseases found.
A varicocele, another scrotal mass, is caused by increased pressure within the venous drainage of the testicle with subsequent dilatation of the veins, producing a mass. Because of the anatomy of the venous drainage, 90% of varicoceles occur on the left side.
Infections of the epididymis or testis can cause an inflammatory infiltrate and swelling. In female individuals, infection of the Bartholin gland in the labia creates an abscess and results in an acute, painful mass.
Location, acuity, and patient age aid in establishing the differential diagnosis. Nonacute masses, which have a slow onset and are not painful, include lymphadenopathy, a retractile testis, hydrocele, hernia, varicocele, tumor, and ectopic ovary. Acute masses that have a sudden onset and are associated with pain include epididymitis, orchitis, testicular torsion, traumatic hematoma, torsion of the appendix testis, lymphadenitis, and incarcerated hernia (Box 108.3).
Skin changes can mimic an acute scrotal mass. Henoch-Schönlein purpura, a vasculitis of unclear etiology, can manifest in the scrotal area. Scrotal edema can also occur acutely.
Testicular torsion occurs most commonly in the newborn period and again at puberty. Incarcerated hernias occur most often in the first 6 months after birth. Varicoceles are almost always noted in adolescence and are located in the upper left area of the scrotum. Testicular tumors occur most commonly in adolescence.
The sex of the patient influences the differential diagnosis of the lesion as well as the workup.
A thorough, focused history helps define the differential diagnosis (Box 108.4). Inquiring about systemic symptoms should always be included and, if present, may be suggestive of a more generalized process, such as a tumor or systemic infection. Symptoms of dysuria are suggestive of epididymitis or orchitis. A history of trauma or possible sexual abuse should always be sought. The patient with hernia or testicular torsion may have a positive family history for the same condition.
Box 108.3. Differential Diagnosis of Inguinal Masses
•Idiopathic scrotal swelling
•Torsion of appendix testis