Autoimmune hemolytic anemia complicating a chronic neutrophilic leukemia: A case report of a rare association

KEY CLINICAL MESSAGE: Chronic neutrophilic leukemia is a rare disease with a poor prognosis. Its diagnosis is challenging in the lack of genetic tools. It can infrequently be associated with autoimmune hemolytic anemia. ABSTRACT: Chronic neutrophilic leukemia is a rare disease with poor prognosis, characterized by a sustained mature neutrophilic leukocytosis in the absence of monocytosis or basophilia with few or no circulating immature granulocytes, hepatosplenomegaly, and granulocytic hyperplasia of the bone marrow. In addition, no molecular markers for other myeloproliferative neoplasms are detected. The 2016 WHO classification included the presence of the CSF3R mutation as a key diagnostic criterion for this disease. Although anemia may be present at diagnosis, hemolytic one rarely complicates myeloproliferative neoplasms. Treatment is largely based on cytoreductive agents, but bone marrow allograft remains the only curative option. We report the case of a patient with chronic neutrophilic leukemia associated with autoimmune hemolytic anemia. We describe the epidemiological, clinical, prognostic, and therapeutic features of this disease in addition to the difficulties of its diagnosis and management in Tunisia.