Differential Diagnosis for Elevated Monocytes and Lymphadenopathy
Single Most Likely Diagnosis
- Infectious Mononucleosis: This condition, caused by Epstein-Barr virus (EBV), is characterized by elevated monocytes, lymphadenopathy, and often, fever and sore throat. The presence of these symptoms together makes it a leading consideration.
Other Likely Diagnoses
- Tuberculosis (TB): TB can cause lymphadenopathy and elevated monocytes as part of its immune response. It's a common condition worldwide and should be considered, especially in endemic areas or in individuals with risk factors.
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with lymphadenopathy. While not all lymphomas will have elevated monocytes, some types, especially those with a high proliferation rate, might show monocytosis.
- Chronic Lymphocytic Leukemia (CLL): CLL is a type of cancer that affects the blood and bone marrow, characterized by the production of an excessive number of immature white blood cells, known as lymphocytes. It can also lead to elevated monocytes in some cases.
Do Not Miss Diagnoses
- HIV Infection: HIV can cause lymphadenopathy and alterations in blood cell counts, including monocytosis. Early diagnosis is crucial for treatment and prevention of complications, making it a "do not miss" diagnosis.
- Castleman Disease: This rare disorder can present with lymphadenopathy and systemic symptoms. It's critical to diagnose because it can be associated with serious complications, including lymphoma and autoimmune disorders.
- Sarcoidosis: Although more commonly associated with granulomatous disease, sarcoidosis can cause lymphadenopathy and sometimes alterations in white blood cell counts, including monocytes.
Rare Diagnoses
- Kikuchi-Fujimoto Disease: A rare, self-limiting condition that presents with lymphadenopathy, often accompanied by fever and night sweats. It's more common in young women and can mimic lymphoma or TB.
- Rosai-Dorfman Disease: A rare histiocytic disorder that can cause lymphadenopathy and sometimes elevated monocytes. It's often self-limiting but can be aggressive in some cases.
- Histiocytic Necrotizing Lymphadenitis (Kikuchi Disease): Similar to Kikuchi-Fujimoto Disease, it's a rare condition with lymphadenopathy and systemic symptoms, which can mimic more serious diseases like lymphoma.