Lymphadenopathy
Lymphadenpathy is due to:
- Proliferation of cells intrinsic to the lymph node (lymphocytes, plasma cells, monocytes or histiocytes or
- Proliferation of cells extrinsic to the lymph node (malignant cells or neutrophils)
Reactive hyperplasia:
- Polyclonal proliferation of one or more cell types in lymph nodes
- Most frequent cause of lymphadenopathy in children
Leukemia, Hodgkin Lymphoma (HL), Non Hodgkins Lymphoma (NHL) and other malignancies can present with lymphadenopathy and or a mediastinal mass.
Below is a PET/CT scan of a patient with Hodgkin lymphoma. He has a large, upper, mainly left sided mediastinal mass (#2). Contiguous with this are involved lymph nodes in the left supraclavicular fossa. #1 points to normal brain, #3 to normal heart and #4 to normal bladder.
Investigations for lymphadenopathy in a child :
- Chest X-ray to check for mediastinal adenopathy
- CT scan of the chest if there is any suggestion of abnormality
- Ultrasound scan of abdomen to look for hepatomegaly, splenomegaly and retroperitoneal adenopathy
- Possible CT scan of abdomen and pelvis to look at intra-abdominal organs, retroperitoneal and pelvic lymph nodes and any possible tumor masses.
Table : Differential Diagnosis of lymphadenopathy
| Inflammatory | Infection | Viral - Epstein-Barr virus, CMV, RSV, HIV, herpes simplex, rubellla, rubeola, coxsackie virus, adenovirus, varicella, influenza |
| Bacterial - TB & atypical mycobacterium, streptococcal or staphylococcal | ||
| Pirochetal - syphilis, rickettsia | ||
| Fungal - coccidiomycosis, histoplasmosis | ||
| Protozoal - Toxoplasmosis | ||
| Post-vaccination - small pox, live attenuated measles | ||
| Non Infectious | Connective Tissue Disorders (Rheumatoid arthritis) | |
Toxic |
Serum sickness | |
| Drug Reaction | Dilantin, allopurinol | |
| Neoplasia | Benign | Langerhans cell histiocytosis |
| Malignant | Non Hodgkin Lymphoma | |
| Hodgkin lymphoma | ||
| leukemia | ||
| Metastatic adenopathy from primary (nasopharyngeal tumor), rhabdomyosarcoma, thyroid cancer. | ||
| Systemic diseases | Lymphoproliferative Disorders |
Angioimmunoblastic lymphadenopathy |
| X-linked lymphoproliferative syndrome | ||
| Castleman disease | ||
| Post-transplant lymphoproliferative disorder | ||
| Storage diseases | Gaucher disease, Niemann-Pick disease | |
| Immunodeficiency States | Chronic granulomatous disease | |
| Sarcoidosis |
