Adenopathy In Adults

I. Introduction

Normal lymph nodes are usually less than 1 cm in diameter and tend to be larger in adolescence than in later life.

Localized lymphadenopathy involves lymph node one while generalized lymphadenopathy involves lymph node more than one.

II. Causes

+ Localized lymphadenopathy  :

 Cervical: the anterior cervical lymph nodes are either superficial or deep to the sternocleidomastoid muscle and the posterior cervical nodes are posterior to the sternocleidomastoid muscle and anterior to the trapezius muscle. The anterior cervical lymph nodes are often enlarged because of infections such as Epstein-Barr virus (EBV), Cytomegalovirus infection, or Toxoplasmosis. Posterior cervical lymphadenopathy may occur with EBV infection, tuberculosis, lymphoma, or head and neck malignancy. Infection with mycobacterium tuberculosis or atypical mycobacteria is suspected when enlarged cervical nodes develop over weeks to months and become fluctuant or matted without significant inflammation or tenderness and sometimes associated with fever. Infection with Bartonella henselae, cat scratch disease, can also have enlarged cervical lymph nodes.
Hard cervical lymph nodes presented in smokers and old patients, we should think more about metastatic head and neck cancer ( eg, oropharynx, nasopharynx, larynx, thyroid, or esophagus).

 Preauricular: They are commonly enlarged in conjunctivitis caused by viral or bacterial pathogens.

 Postauricular: Rubella infection is a common disease for the suboccipital node.

 Suboccipital: The nodes receive drainage from the posterior scalp and are commonly involved in bacterial or fungal infections.
 Supraclavicular: it is associated with a high risk of malignancy. Right supraclavicular adenopathy is associated with cancer in the mediastinum, lungs, or esophagus. Left supraclavicular adenopathy suggest abdominal malignancy  ( eg, stomach, gallbladder, pancreas, kidney, testicles, ovaries, lymphoma, or prostate)

 Axillary: The axillary nodes receive drainage from the arm, thoracic wall, and breast. Infections, including cat scratch disease, are common causes of axillary lymphadenopathy. In the absence of upper-extremity lesions, cancer is often found.
 Epitrochlear: The differential diagnosis includes infections of the forearm or hand, lymphoma, sarcoidosis, tularemia, and secondary syphilis.
Inguinal: Inguinal lymphadenopathy is usually caused by lower-extremity infection, sexually transmitted diseases ( such as chancroid, lymphogranuloma venereal, genital herpes, syphilis ), or cancer.

+ Generalized lymphadenopathy : 

It may be a feature of a number of systemic diseases. The following are some common or especially important diseases.

HIV infection: Nontender adenopathy primarily involving the axillary, cervical, and occipital node develops in the majority of individuals during the second week of acute symptomatic HIV infection.
Mycobacterial infection: Nodes are typically nontender, enlarge over weeks to months without prominent systemic symptoms, and can progress to matting and fluctuation
 Infectious mononucleosis: it is characterized by the triad of moderate to high fever, pharyngitis, and lymphadenopathy. Lymph node involvement is typically symmetric and involves the posterior cervical more than the anterior chain. Lymphadenopathy peaks in the first week and then gradually subside over two to three weeks. Infections,mononucleosis-like illnesses include cytomegalovirus, human herpesvirus 6, HIV, adenovirus, herpes simplex virus, Streptococcus pyogenes, and Toxoplasma gondii.
 Systemic lupus erythematosus: enlarged lymph nodes appear in 50 percent of patients with systemic lupus erythematosus (SLE). The nodes are typically soft, non-tender, and discrete, varying in size from 0.5 to several cm and detected in the cervical, axillary and inguinal areas. Lymph node enlargement can also be the result of infection or a lymphoproliferative disease in SLE.
 Medication: Phenytoin can cause generalized lymphadenopathy in the absence of a serum sickness reaction. Serum sickness has manifestations including fever, arthralgias, rash, and generalized lymphadenopathy.
 Sarcoidosis: sarcoidosis most frequently involves the lung. Peripheral lymphadenopathy is present in up to 40 percent of patients. Common presenting respiratory symptoms include cough, dyspnea, and chest pain.
 Lymphoma: Hodgkin or non-Hodgkin lymphoma may present with painless, firm, peripheral lymphadenopathy. Hodgkin lymphoma presents with neck ( cervical and/or supraclavicular) lymphadenopathy.
Kawasaki disease: Kawasaki disease, is an uncommon illness. It is the most frequent cause of childhood vasculitis. This syndrome is associated with fever, cervical lymphadenopathy, and a variety of other symptoms including conjunctivitis, mucositis, rash, and coronary artery aneurysms.
Amyloidosis: Amyloid can be deposited in lymph nodes and is a rare cause of lymphadenopathy in the absence of amyloid infiltration of other organs.

III. Evaluation

 Localizing signs or symptoms suggesting infection or malignancy
 Exposures likely to be associated with infection ( eg cat scratches), undercooked meat ( toxoplasmosis), high-risk behavior ( eg sexual behavior, injection drug use ).
 Constitutional symptoms such as fever, night sweats, or weight loss suggesting tuberculosis, lymphoma, or other malignancy.

IV. Diagnostic Approach

Patients of any age in whom there is a concern for malignancy based on characteristics of the lymph node ( eg, firm node, rapid increase in size of the node, or location such as supraclavicular nodes), symptoms( eg, systemic complaints of fever, night sweats, weight loss), and/or patients characteristics( eg, firm cervical nodes in older patients who are smokers, axillary nodes in older women ) should appropriate evaluation for malignancy.