Invasive Mucormycosis in a Chronic Lymphocytic Leukemia Patient on Zanubrutinib: A Case Report

Invasive mucormycosis is a severe fungal infection that predominantly affects immunocompromised and diabetic patients. This case study highlights the importance of early diagnosis and pathogen-specific antifungal therapy in managing invasive mucormycosis among high-risk patients.

A 47-year-old male with chronic lymphocytic leukemia (Rai stage IV) on zanubrutinib and with uncontrolled diabetes was admitted to Jiangxi Cancer Hospital on November 7, 2021. Imaging revealed pulmonary infection and splenic infarction, while laboratory findings suggested disseminated intravascular coagulation. Despite empirical broad-spectrum antibiotics, his condition worsened, necessitating an emergency splenectomy. Postoperatively, fluconazole was added to his antimicrobial regimen, but he developed respiratory failure, liver and renal dysfunction, and persistent hyperglycemia. A bronchial alveolar lavage sample was sent for metagenomic next-generation sequencing (mNGS) to identify the pathogen. Despite intensive care, he deteriorated rapidly, developing myocardial injury, metabolic acidosis, and multiorgan failure, leading to death on November 13, 2021. mNGS results, received after the patient's death, identified Rhizomucor pusillus as the primary pathogen, with co-infection by Enterococcus faecium and Human betaherpesvirus 7.

This study presents a case of rapidly progressive mucormycosis co-infected with bacterial and viral pathogens, highlighting the importance of early intervention and accurate diagnosis. Delayed identification of the fungal pathogen significantly hindered timely antifungal intervention, underscoring the importance of appropriate empirical therapies in hematological patients treated with zanubrutinib. Future research should focus on antifungal stewardship and epidemiological surveillance studies to improve early detection and guide targeted empirical treatment for high-risk populations.