Langerhans cell histiocytosis (LCH) could stem from disrupted blood cell development, leading to the abnormal expansion of certain cell types, according to a poster presentation from AACR Annual Meeting 2024. Haadi Ali, MD, and colleagues conducted an analysis of 76 patients, examining demographics, diagnostic approaches, and treatment outcomes, with a special focus on monocyte counts during disease onset, progression, and after therapy. The researchers identified diverse disease manifestations with CT, PET, and MRI as common diagnostic tools. Out of 49 patients, 17 showed complete responses, particularly among those receiving localized treatment. However, researchers observed progression in five smokers with pulmonary LCH. Monocyte counts were signifi-cantly increased during disease progression (0.94 K/µL) compared with counts after therapy reinstatement (0.31 K/µL), suggesting a potential marker for monitoring disease activity. Dr. Ali and colleagues wrote that their findings suggest LCH involves dysregulated hematopoiesis and monocyte differentiation, contributing to disease pathology
