Pulmonary Langerhans Cell Histiocytosis Presenting as a Solitary Pulmonary Nodule on a Lung Cancer Screening CT

Figure 3

Histologic features of the pulmonary nodule. (a) Low magnification image shows a solid appearing nodule with indistinct edges (hematoxylin-eosin stain, original magnification 8x). (b) A high magnification view exhibits marked reactive alveolar type II cell hyperplasia. The alveolar septa are expanded and contain scattered eosinophils (hematoxylin-eosin stain, original magnification 400x). (c) Another high magnification view shows alveolar macrophage accumulation at the edge of the nodule (hematoxylin-eosin stain, original magnification 400x). (d) Immunohistochemistry for langerin reveals clusters of Langerhans cells within the nodule (original magnification 400x).

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