Mononucleosis syndrome and acute monocytic leukemia

Area of Science:

• Hematology
• Virology
• Oncology

Background:

• Infectious mononucleosis is typically caused by Epstein-Barr virus (EBV) or cytomegalovirus (CMV).
• Patients with compromised immune systems, such as those with acute leukemia, are susceptible to opportunistic infections.
• Mononucleosis syndrome from other viral agents is uncommon.

Observation:

• A patient diagnosed with acute monocytic leukemia (AMoL) experienced a mononucleosis syndrome during the bone marrow recovery phase post-chemotherapy.
• The mononuclear leukocytes observed during this syndrome bore a striking resemblance to the patient's initial leukemic cells.
• The syndrome was definitively linked to varicella zoster virus (VZV) infection, confirmed by a subsequent characteristic herpes zoster rash.

Findings:

• Varicella zoster virus (VZV) can manifest as a mononucleosis syndrome, even in the context of acute monocytic leukemia.
• The clinical presentation of VZV-induced mononucleosis syndrome can mimic leukemic relapse due to similar-looking mononuclear leukocytes.
• Delayed diagnosis of VZV mononucleosis syndrome is possible, underscoring the need for comprehensive etiological investigation.

Implications:

• This case expands the known spectrum of VZV infections in immunocompromised individuals.
• It emphasizes the importance of considering atypical viral etiologies for mononucleosis-like syndromes in leukemia patients.
• Awareness of VZV mononucleosis syndrome is crucial for accurate diagnosis and appropriate management, preventing misdiagnosis of leukemic recurrence.