Faces of Cellular Reactions and Infiltrations in the Lungs Infection Inflammation Inhalation Smoking and the Alveolus –The effect of the proteases and and elastases cause destruction of the alveoli and loss of elasticity, and therefore overall function. The destruction leads to bullous diseaseThe accumulation of smokers macrophage, and in the case of Langerhans cell histiocytosis leads to space occupation of the alveoli also reducing functionAshley DavidoffTheCommonVein.netlungs-00687 Immune Langerhans Langerhans Dendritic MacrophageAshley Davidoff MDTheCommonVein.net CT CORONAL VIEW – UPPER ZONES MORE AFFECTED THAN LOWER LUNG ZONES – LANGERHANS HISTIOCYTOSIS53-year-old female with nicotine dependence presents with dyspnea and coughCXR (PA and Lateral) shows bilateral and extensive reticular nodular changes slightly more prominent in the upper lung zonesCT scan from 16 months prior showed multiple relatively thick-walled cysts predominantly in the upper lobes. The cysts are round and air filled large and are between 5mm-8mmCT scan 9 months later shows improvement in the thickened walls of the cysts but maintenance of diffuse cystic changes predominantly in the upper lobesA CT scan done 2 years later shows no significant change in the diffuse bilateral cystic changes, dominant in the upper lobes and consistent with Langerhans histiocytosisAshley Davidoff MD DIP Macrophages Eosinophils Chronic Eosinophilic Pneumonia Affects the Alveoli and Alveolar Septal Interstitium Chronic eosinophilia is characterised by alveolar filling with eosinophils and inflammatory exudates(a) and interalveolar interstitial thickening, (overlaid in red in b). The infiltrates are classically peripherally positioned, usually upper lobes, more commonly bilateral but can be unilateral, and manifest as consolidation and or ground glass opacities. The CT shows a peripheral consolidation in the left upper lobeAshley Davidoff MD The CommonVein.net lungs-0764 Malignancy Lepidic Growth Ground Glass Opacity and Adenocarcinoma with Lepidic GrowthThe Ground Glass Opacity (GGO) in this case is caused by partial filling of the alveolus with malignant cells Ground glass opacification may be caused by partial filling of the alveolus with cellular material resulting in partial replacement of air with solid material. The net density is gray rather than white in the situation where the alveolus is fully replaced with cells or fluid. There is blending of the black of the subtending airways and the white of the vessels with the gray density of the cellular infiltrate and hence the normal vessels are not visualized in ground glass opacities.Ashley Davidoff MD TheCommonVein.net 134375b01 Mechanical/Atelectasis Trauma Metabolic Circulatory- Hemorrhage Immune Infiltrative Idiopathic Iatrogenic Idiopathic