by Alberto J. Muniagurria and Eduardo Baravalle

The enlargement or consistency of the lymph nodes is called adenopathy or adenomegaly. The node may become enlarged due to an increase in the number and / or size of the lymphoid follicles due to proliferation of lymphocytes or reticuloendothelial cells or due to neoplastic infiltration. Ganglion cell proliferation occurs in response to any stimulus that increases phagocytic activity or in response to antigens or neoplastic proliferation. Nodal cell infiltration can be produced by neoplastic, leukemic, polymorphonuclear cells, or macrophages filled with substances, as in deposition diseases. Sometimes it is a clinical manifestation of a local pathology and other times, of a systemic disease.

The presence of lymphadenopathy is of greater semiological importance in adults than in children, because children respond with generalized lymphadenopathy to minor stimuli.

Occasionally, some benign-appearing lymphadenopathy can be a manifestation of a serious systemic disease.

The patient may consult due to lymph node enlargement, or sometimes it is an important finding on physical examination. Lymphadenopathy may or may not be painful, accompanied by congestive signs of the skin, adhering to neighboring tissues or not, and its consistency varies from soft to stony.

Hard, non-mobile, painless lymph nodes without inflammatory signs suggest neoplasms, while in acute infection the lymph node is painful, with increased temperature, and is mobile.

Head and neck lymphadenopathies are linked to pathologies of the ear, nose, mouth and throat. In 35% of head and neck tumors, the first manifestation is a metastasis in the cervical nodes. The patient's symptomatology guides them to think about a certain disease.

Thus fever, sweat, weight loss, and itching point to malignant lymphoma. A recent throat infection along with splenomegaly suggests infectious mononucleosis, while contact with cats suggests toxoplasmosis. Certain medications, such as phenytoin, can cause lymphadenopathy. The left retroclavicular node, known as Troisier's node, is the seat of metastasis from gastric cancer or other abdominal neoplasms: pancreas, ovaries, testis or kidney. Uterine cancers can manifest with cervical lymphadenopathy. The right retroclavicular ganglion can be enlarged due to diseases originating in the chest, either pulmonary or mediastinal.

When accompanied by a rash or fever, retroauricular or occipital lymphadenopathies suggest the presence of rubella. Anterior atrial adenopathies are associated with oculo-nodal syndrome (Chagas, tularemia, trachoma, cat scratch fever, syphilis, tuberculosis).

Dental or oropharyngeal infections can cause submaxillary adenopathy.

Finding axillary lymphadenopathy requires careful evaluation of the breasts. Lymphomas can also present with lymph node hypertrophy in this location. Epitrochlear adenopathies are common in lymphomas and secondary syphilis.

Inguinal lymphadenopathies are often caused by bacterial or fungal skin infections of the lower limbs, although they are also the seat of venereal infections such as lymphogranuloma venereum and chancre. Primary syphilis of the genitalia is associated with bilateral satellite adenopathy. Sometimes they can be metastatic, and in these cases their origin must be sought in the rectum, vagina and uterus.

The hilar adenopathies seen on the chest film can be unilateral, as occurs in metastatic lung carcinoma and tuberculosis, or bilateral asymmetric, common in Hodgkin and non-Hodgkin lymphomas, in sarcoidosis, in tuberculosis and in coccidioidomycosis.

Adenopathies are a manifestation of a systemic disease: toxoplasmosis, rheumatoid arthritis, serum sickness, hyperplasia caused by phenytoin, lymphomas, acute and chronic lymphocytic leukemias, infectious mononucleosis, histiocytosis, brucellosis, cytomegalovirus infection, tuberculosis, infectious hepatitis, secondary infection histoplasmosis.

The most common causes of lymphadenopathy are:

1. Reactive
   1. Infectious:
      • Bacterial (pyogenic and tuberculosis).
      • Viral (cytomegalovirus, infectious mononucleosis).
      • Mycotic (coccidioidomycosis).
      • Parasitic (toxoplasmosis).
   2. Non-infectious:
      • Sarcoidosis.
      • Connective tissue disease.
      • Dermatological.
      • Drug-induced (phenytoin).
2. Infiltrative
   1. Benign
      • Histiocitosis
      • Lipidosis.
   2. Evil
      • Primary lymphoma
      • Metastatic carcinoma.