CLCs are associated with EETosis in human tissues. (A-B) Tissue CLCs in biopsies of frontal sinus (A, allergic patient) and bacterially infected colon (B, ulcerative colitis) with a large number of FEGs released by infiltrating lytic eosinophils. Note hexagonal crystals and chromatolytic nuclei (N). Samples were prepared for conventional TEM. (C) Evaluation of CLCs in nasal polyps from ECRS patients. (i) Arrows indicate typical CLCs (40× objective). Note the abundant eosinophils with chromatolysis and FEGs. (ii) The percentage of CLC-positive patients was assessed by hematoxylin and eosin staining according to clinical severities. Assessment of CLCs and detailed study subject information are provided in the supplemental materials. Numbers represent CLC-positive patients/total patients in each group. (D) Maximal projection of 3-dimensional z-stack images of galectin-10 (green) and MBP (red) staining of nasal polyps from ECRS patients. (i) A region of lesser eosinophil infiltration exhibiting intact eosinophils; (ii) a highly inflamed lesion with abundant CLCs. In panel Di, eosinophils with bilobed nuclei (blue) showed cytoplasmic/perinuclear galectin-10 staining. In contrast, small punctate galectin-10 and loss of cytoplasmic CLC with extracellular MBP were observed in panel Dii. CLCs with a bipyramidal structure (arrows) were stained with galectin-10. Images were obtained with a Carl Zeiss LSM780 confocal microscope (100× objective). The scale shows each 10 µm.