Differential Diagnosis of Lymphadenopathy

The differential diagnosis for lymphadenopathy is broad and can be categorized based on the likelihood and potential impact of missing a diagnosis. Here's a structured approach:

• Single Most Likely Diagnosis
  • Reactive Lymphadenitis: This is often the most common cause of lymphadenopathy, resulting from a viral or bacterial infection. It's usually self-limiting and resolves without specific treatment.
• Other Likely Diagnoses
  • Tuberculosis (TB): Especially in endemic areas or in individuals with risk factors such as immunocompromised states or recent travel to high-prevalence areas. TB can cause significant morbidity if not treated.
  • Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with lymphadenopathy. The diagnosis is crucial as it requires specific treatment.
  • Metastatic Cancer: Cancers such as breast, lung, and head and neck cancers can metastasize to lymph nodes, presenting as lymphadenopathy.
• Do Not Miss Diagnoses
  • HIV Infection: Early stages of HIV infection can present with lymphadenopathy, and missing this diagnosis can have significant implications for the patient's health and public health.
  • Cat-Scratch Disease: Caused by Bartonella henselae, this condition can lead to significant lymphadenopathy and systemic symptoms if not treated.
  • Lymphogranuloma Venereum (LGV): A sexually transmitted infection caused by certain serovars of Chlamydia trachomatis, which can cause lymphadenopathy and other systemic symptoms.
• Rare Diagnoses
  • Sarcoidosis: A systemic granulomatous disease that can cause lymphadenopathy among other symptoms.
  • Kikuchi Disease: A rare, self-limiting condition that predominantly affects young women and presents with lymphadenopathy and fever.
  • Castleman Disease: A rare disorder that involves an overgrowth of cells in the lymphatic system, which can cause lymphadenopathy.

Each of these diagnoses has a different set of implications for patient management and outcomes, emphasizing the importance of a thorough diagnostic workup for lymphadenopathy.