Approach Considerations
Lymph node enlargement is a common feature of various benign and malignant disorders that affect children. If the history and physical examination are thorough, the etiology of most lymphadenopathies can be determined without further investigation. However, if the diagnosis requires confirmation or is in doubt, the results from a carefully chosen combination of skin tests, serologic tests, and/or diagnostic imaging tests may establish the correct diagnosis. If the diagnosis is still unclear or if tissue is required in the case of a potential malignancy, the results from a careful lymph node biopsy can most certainly confirm the correct diagnosis.
An absolute contraindication for lymph node biopsy is recognized if the etiology is clear and if the lymphadenopathy is expected to improve with no further management. A relative contraindication is recognized if the suspected etiology can be treated expectantly (eg, in cases of bacterial infection of the node where administration of antibiotics is expected to improve the clinical scenario without a need for biopsy). Another relative contraindication is acknowledged if an anterior mediastinal mass is noted on chest radiography and considered to be a high anesthetic risk. In this situation, the anesthetic risks must be balanced against the need for obtaining tissue.
Lymphadenopathy is present in a vast array of disorders, and discussing the future of lymphadenopathy is difficult because of the number of diseases involved. The diagnosis of lymph node disorders will improve as molecular tools become more available. Having these tools will allow clinicians to diagnose the etiology with more exact science and less invasive means. The use of fine-needle aspiration (FNA) biopsy (FNAB) in children will become more frequent as more experience is obtained in centers that had not been employing this technique in pediatric cases. [27, 20]
Medical Therapy
The medical therapy chosen is based on the most likely etiology if a biopsy has not been performed.
In the case of bacterial infection, the most likely culprits include Staphylococcus and Streptococcus species; therefore, a beta-lactamase–resistant antibiotic is chosen. In patients with tuberculosis, rifampin and isoniazid are chosen.
In cases of nontuberculous mycobacterial adenitis, most still advocate surgical management. However, some patients with lymphadenopathy in anatomic locations of concern may benefit from drugs such as clarithromycin, azithromycin, rifampin, rifabutin, or ethambutol. [28]
Most patients with viral etiology for lymphadenopathy may be treated expectantly.
Patients with some of the more obscure diagnoses, such as Kawasaki disease, systemic lupus erythematosus (SLE), and Langerhans cells histiocytosis, may require immunosuppressants.
Surgical Therapy
Enlargement of a cervical lymph node to a diameter of 1 cm or greater is regarded as abnormal and warrants consideration of biopsy if the diagnosis is otherwise uncertain. Biopsy of the lymph node may involve one of two methods. The most commonly used method is the surgical biopsy, in which either a portion of the node or the complete node is excised.
Before the procedure, the patient and family are instructed in the steps involved and the risks and benefits; a consent form is obtained. Before removal of the node, the surgeon should discuss the case with the pathologist so that the appropriate tests may be immediately performed after the specimen is received. The procedure is performed either in the operating room suite with general anesthesia or in a minor procedure room with conscious sedation.
Procedural details
An incision is made in the skin overlying the enlarged node, and the surrounding tissue is carefully dissected away from the node. Care must be taken to avoid surrounding nerves, especially in areas around the neck. To assist in the removal of the node, a suture on a noncutting needle may be placed through the center of the node to provide traction so that it can be pulled into view (see the images below). This measure also minimizes crush artifact that may result from excessive handling of the lymph node.
A lymph node biopsy is performed. Note that a marking pen has been used to outline the node before removal and that a silk suture has been used to provide traction to assist the removal.
A lymph node after removal by means of biopsy, which was performed completely under a local anesthetic technique.
The node must then be sent fresh to the pathologist for processing (see the image below). This is to allow all possible tests to be performed; fixation of the lymph node precludes performance of some important tests (eg, flow cytology, cytogenetics). Usually, one large node or a group of smaller nodes is sent to the pathologist for diagnosis.
A gross image of a node following excision. The cut surface of the node shows the typical fish-flesh appearance seen with lymphoma.
Although lymph node biopsy via an open technique has been the standard approach, the advent of minimally invasive techniques has led surgeons to apply these methods to lymph node biopsies in the thoracic cavity and the abdomen.
Whereas percutaneous lymph node biopsy guided by ultrasonography (US) or computed tomography (CT) often does not supply sufficient tissue for histopathologic diagnosis of a lymphoma, laparoscopic lymph node biopsy has the advantage of obtaining the entire lymph node while avoiding the invasiveness and possible complications of a laparotomy. [29]
Postprocedural Care
Lymph node biopsies are usually performed on an outpatient basis. Before the patient is discharged from the hospital, the wound is assessed for swelling and bleeding. The wound area should be kept dry for at least 2 days, and appropriate analgesia should be administered.
Patients and their families should be contacted with the results as soon as the report is finalized. If further therapy is necessary, patients should return to the hospital or be referred to the appropriate specialists for therapy.
Complications
The known complications of the biopsy itself arise from injury to surrounding structures around the node, including soft tissue, blood vessels, and nerves. Other potential complications in patients with malignancy include the following:
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Spread of tumor cells in the area of the biopsy
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Production of a draining sinus in the case of atypical mycobacterial infection (if the entire node is not excised)
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Risks associated with general anesthetics, especially if the patient has an anterior mediastinal mass
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A preoperative radiograph showing a narrowed trachea secondary to an anterior mediastinal mass.
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A CT scan showing an anterior mediastinal mass and compression of the trachea.
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A CT scan showing an anterior mediastinal mass and compression of the left mainstem bronchus.
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A lymph node biopsy is performed. Note that a marking pen has been used to outline the node before removal and that a silk suture has been used to provide traction to assist the removal.
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A lymph node after removal by means of biopsy, which was performed completely under a local anesthetic technique.
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A gross image of a node following excision. The cut surface of the node shows the typical fish-flesh appearance seen with lymphoma.
