A Case of Chronic Lymphocytic Leukemia Coinciding With COVID-19.

Comorbidities including leukemia are risk factors in coronavirus disease 2019 (COVID-19) patients for high morbidity and mortality. The severity of the disease is usually correlated with lymphopenia. On the other hand, we came across a case of marked absolute lymphocytosis in a COVID-19 patient, which further escalated five-fold during his hospital stay. Subsequently, the diagnosis of chronic lymphocytic leukemia (CLL) was made following positive cell surface markers for CD19+, CD5+, and CD20+ (dim), in the presence of restricted immunoglobulin light chain of lambda type on flow cytometry. Numerous cases are available in the literature of COVID-19 among established CLL patients. However, we are mentioning here the second case where the diagnosis of CLL was established accidentally during the work-up for lymphocytosis in COVID-19 infection.