The Persistence of COVID-19-Related Pancytopenia as A Possible Sign of Hairy Cell Leukemia: A Case Report

COVID-19 is known to cause many hematological abnormalities, such as thrombocytopenia, leucopenia, and lymphopenia. Pancytopenia, a decrease in all peripheral blood cell lines, is a rare complication not commonly seen in patients with COVID-19. We report a case of a patient who experienced COVID-19 infection with mild clinical symptoms like fever, fatigue, and muscle and bone aches. The laboratory examinations revealed pancytopenia, mainly neutropenia, thrombocytopenia, mild anemia, and relative lymphocytosis, which persisted after infection resolution. The splenomegaly in abdominal echography and the characteristics of lymphocyte elements in peripheral blood smear examination raised suspicion of the presence of hairy cell leukemia (HCL); therefore, the patient was further examined with a bone marrow biopsy, which confirmed the diagnosis. The persistence of pancytopenia after recovery from COVID-19 infection, especially in patients with splenomegaly, should raise suspicion of another hematological coexistence diagnosis like HCL.