Pulmonary LCH : Morphology
Pulmonary Langerhans Cell Histiocytosis (LCH) - Morphology: The interstitial infiltrates are composed of clusters of Langerhans cells (LCs), variable number of eosinophils, pigment-laden macrophages, lymphocytes, plasma cells and neutrophils. Eosinophils may be entirely absent or so numerous as to produce eosinophilic microabscesses with central necrosis and Charcot-Leyden crystals.
Early lesions of LCH are cellular and show numerous LCs and eosinophils with minimal or no fibrosis. Later stages are dominated by fibrosis and foamy macrophages with decreased numbers of LC cells and eosinophils. LCs have moderate to abundant lightly eosinophilic cytoplasm and vesicular nuclei with grooves, folds and indentations.