Light micrograph of tissue from the sinuses of a patient with chronic sinusitis. The top part of the picture shows respiratory type epithelium, which is the normal lining of the sinus space. There are many inflammatory cells (small round blue or red dots) beneath the respiratory epithelium. The inflammatory cells are present throughout, but are more numerous on the right side of the image. Haematoxylin and eosin stained tissue section. Magnification: 100x when printed at 10 cm.