Cyclic Neutropenia Mimicking Crohn’s Disease: Two Case Reports and a Narrative Review

Abstract

Cyclic neutropenia is a rare hematological condition characterized by periodic fluctuations in neutrophil counts, with a 21-day periodicity. Clinical presentation varies from mild to severe forms of the disease, with the onset of recurrent fever, painful oral ulcers, recurrent bacterial infections, peritonitis and septic shock. The availability of granulocyte colony-stimulating factor (G-CSF) has revolutionized the management and natural history of this disease, regulating the proliferation, differentiation and maturation of the progenitor cells, reducing the duration of neutropenia. Inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), is a group of chronic pathologies with involvement of the gastrointestinal tract. Symptoms include diarrhea, abdominal pain, fever, weight loss and extraintestinal manifestations (EIMs). In recent years, the focus of IBD therapy, including conventional therapies and biological therapies, has moved from treatment of symptoms to "deep remission" of the disease. The association between cyclic neutropenia and CD is rarely reported in the literature. Here, we describe two case reports of patients who underwent surgery because of diagnosis of complicated CD. After surgery, because of persistent neutropenia, the hematologist consultant confirmed suspicions of cyclic neutropenia and therapy with G-CSF was started with benefits, underlining the crucial importance of proper differential diagnosis.