Differential Diagnosis for 40 y/o Female with Cervical Lymphadenopathy and Positive Mono Spot Test
- Single Most Likely Diagnosis
- Infectious Mononucleosis (IMN): This is the most likely diagnosis given the positive mono spot test, which is a rapid test used to diagnose IMN caused by Epstein-Barr virus (EBV). The clinical presentation of cervical lymphadenopathy along with the positive test supports this diagnosis.
- Other Likely Diagnoses
- Toxoplasmosis: Although less common, toxoplasmosis can cause lymphadenopathy and may yield a false-positive mono spot test due to cross-reacting antibodies. It's a consideration, especially if the patient has been exposed to cats or has consumed undercooked meat.
- Cytomegalovirus (CMV) Infection: CMV can cause a mononucleosis-like syndrome with lymphadenopathy and may also lead to a false-positive mono spot test. This diagnosis is plausible, especially in immunocompromised patients or those with recent exposure.
- Acute HIV Infection: The acute retroviral syndrome can present with lymphadenopathy and may mimic IMN. A positive mono spot test could be seen due to polyclonal activation of lymphocytes, although this is less common.
- Do Not Miss Diagnoses
- Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with cervical lymphadenopathy. Although less likely than IMN, missing a diagnosis of lymphoma could have severe consequences, making it crucial to consider, especially if symptoms persist or worsen despite initial treatment for IMN.
- Tuberculosis (TB): TB can cause lymphadenopathy, and while it might not directly relate to a positive mono spot test, it's a critical diagnosis not to miss due to its public health implications and the need for specific treatment.
- Rare Diagnoses
- Other Viral Infections (e.g., Adenovirus, Herpes Simplex Virus): These can occasionally cause lymphadenopathy but are less commonly associated with a positive mono spot test.
- Brucellosis: A zoonotic infection that can cause lymphadenopathy among other symptoms. It's rare and typically associated with specific exposures (e.g., to infected animals or their products).
- Syphilis: Secondary syphilis can present with lymphadenopathy, although it would not typically cause a positive mono spot test. It's a rare consideration but should be kept in mind, especially in patients with risk factors for sexually transmitted infections.