GROIN MASSES

EVA M. DELGADO, MD AND RONALD F. MARCHESE, MD, PhD

There are many different causes of inguinal swelling in children, ranging from inconsequential to serious (Table 29.1). Although hernia is the most common etiology, other important causes include local lymphadenitis, benign or malignant tumors, and pathology related to conditions in which the testicle is found outside the scrotum (retractile, undescended, ectopic, and dislocated); these conditions are discussed in this section. Testicular torsion, scrotal masses, and infections such as epididymitis and orchitis are addressed in Chapter 57 Pallor on scrotal pain, and approach to the incarcerated inguinal hernia is more completely addressed in Chapter 124 Abdominal Emergencies.

GENERAL APPROACH

In evaluating an inguinal mass, consider duration of symptoms, presence/absence of pain, symptoms of obstruction, signs of systemic disease and/or local infection, change in mass with changes in intra-abdominal pressure, trauma and past medical history such as prematurity, abdominal or urogenital malformation, and connective tissue disorder. Careful history and physical examination and judicial use of laboratory tests and ultrasound confirm the diagnosis. The next section includes more detail about common pediatric inguinal mass diagnoses and characteristics specific to each of their presentations. Figure 29.1 reviews the approach to the differential diagnosis.

DIFFERENTIAL DIAGNOSIS

Lymphadenopathy and Lymphadenitis

There are two groups of inguinal nodes: Superficial and deep. The superficial nodes are subdivided into a horizontal chain that runs parallel to the inguinal ligament and a vertical chain located laterally. The horizontal group drains the skin of the lower abdominal wall, perineum, gluteal region, penis and scrotum or the mucosa of the vagina, and the lower anal canal. The vertical group drains lymph from the gluteal region, the penis and deep structures of the scrotum, the anterior and lateral areas of the thigh and leg, and the medial portions of the foot. The deep inguinal nodes, which lie beneath the fascia lata medial to the femoral vein, drain all the superficial nodes, the clitoris or glans of the penis, the medial thigh and leg, and the lateral portion of the foot.

Normal inguinal nodes are less than 1.5 to 2 cm long, and are oval, firm, slightly moveable, and nontender. Lymphadenopathy describes enlarged, nontender nodes, and can be regional or generalized (see Chapter 42 Lymphadenopathy). Isolated inguinal lymphadenopathy may be unilateral or bilateral, and typically develops in response to a local irritation or infection. Inguinal lymphadenopathy associated with generalized lymphadenopathy is associated with systemic diseases including infectious (e.g., human immunodeficiency virus, Epstein–Barr virus), malignant, rheumatologic, or inflammatory processes. Local tumors, such as testicular tumors, can metastasize to the inguinal nodes causing a localized lymphadenopathy.

Isolated inguinal adenopathy most often results from inflammation or infection of the gluteal region, perineum, genitalia, or lower extremities, and therefore, these areas should be examined carefully. Chronic eczema, tinea cruris, or an innocuous inflammation (e.g., an insect bite, diaper rash) may produce lymphadenopathy. In such cases, treatment of the underlying condition suffices.

Lymphadenitis presents as an enlarged, tender node with or without overlying erythema, suppuration, or ulceration. Skin flora, such as Group A β-hemolytic streptococcus and Staphylococcus aureus, are often the source of infection. Children without significant systemic symptoms, pain, or other comorbidities can be treated as outpatients with oral antibiotics effective against these organisms and follow-up. If there is a concern for suppuration, ultrasound is helpful in identifying the presence of phlegmon or abscess (Fig. 29.2). Incision and drainage is the treatment of choice for abscess. If drainage is inadequate, or there is overlying cellulitis an antibiotic effective against MRSA is indicated (see Chapter 102 Infectious Disease Emergencies). Children with severe symptoms from lymphadenitis/cellulitis should be admitted and treated with intravenous antibiotics.

Lymphadenitis can also be associated with zoonotic or sexually transmitted infections. Animal and insect bites occurring on the lower extremity can cause inguinal adenopathy or adenitis. Catscratch disease (Bartonella henselae) results in regional lymphadenopathy that is often red, indurated, and warm. Lymphadenopathy resolves spontaneously within 2 to 4 months. Antibiotic treatment for immune-competent children with mild disease is of uncertain value (see Chapter 102 Infectious Disease Emergencies). Yersinia pestis transmitted via flea bites carries a high mortality and is rare in the United States. Bubonic plague, the most common form, causes regional exquisitely tender lymphadenitis (bubo) with overlying erythema in the area of the bite; the inguinal nodes are the most common site. Ulceroglandular tularemia is transmitted by tick bites and can cause inguinal adenopathy and adenitis that often precedes the appearance of a small papule that later ulcerates at the portal of entry on the lower extremity. Both plague and tularemia exist in pneumonic forms that have become agents of bioterrorism (see Chapter 136 Biological and Chemical Terrorism). Filariasis, a parasitic disease transmitted by fly or mosquito bites and found in the tropics, can produce adenopathy or adenitis associated with lower extremity lymphedema and scrotal pathology. Treatment is dependent on the extent of disease. (See treatment options in Table 29.2.)

Sexually transmitted infections can result in inguinal adenopathy or adenitis (see Chapter 100 Gynecology Emergencies). Herpes simplex is a common cause of genital ulcerations and bilateral lymphadenitis. Occasionally, enlarged lymph glands precede the appearance of vesicles. The chancre of primary syphilis is painless and has a raised, indurated border and a clean surface. Bilateral (70%) or unilateral, nontender inguinal adenopathy is common. Chancroid, more common in developing countries than in the United States, is caused by Haemophilus ducreyi, which is hard to isolate and requires selective media. Unlike syphilis, the chancroid ulcer is painful and nonindurated, and has serpiginous borders and a friable base covered with a gray or dirty yellow exudate. About one-half of patients develop painful adenitis, usually unilaterally. The node or nodes often suppurate and drain spontaneously, but may require needle aspiration or surgical incision.

TABLE 29.1

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