Invasive fusariosis masquerading as extramedullary disease in rapidly progressive acute lymphoblastic leukemia

Area of Science:

• Mycology
• Hematology
• Oncology

Background:

• Invasive fusariosis (IF) is a serious fungal infection typically seen in immunocompromised individuals, especially those with hematologic malignancies and neutropenia.
• Patients undergoing chemotherapy for acute lymphoblastic leukemia (ALL) are at high risk for opportunistic infections.
• Breakthrough fungal infections can occur even with standard antifungal prophylaxis, such as agents targeting Aspergillus species.

Observation:

• A patient with rapidly progressing acute lymphoblastic leukemia (ALL) presented with multiple skin nodules.
• These skin lesions were initially suspected to be chloromatous disease, a known complication of ALL.
• The patient was receiving Aspergillus-active antifungal prophylaxis at the time of presentation.

Findings:

• Pathologic examination confirmed the skin nodules to be invasive fusariosis (IF), occurring concurrently with active leukemia.
• This case demonstrated IF in an ALL patient with normal neutrophil counts, challenging typical clinical presentations.
• The infection occurred despite the patient receiving Aspergillus-active antifungal prophylaxis.

Implications:

• Highlights the critical need for prompt histopathological diagnosis of new skin lesions in ALL patients, irrespective of suspected leukemia progression.
• Underscores that invasive fusariosis can manifest in ALL patients even without neutropenia and despite appropriate antifungal prophylaxis.
• Emphasizes the importance of considering a broader spectrum of fungal pathogens beyond Aspergillus in high-risk hematology patients.