Lymphocyte morphology in middle ear effusions.

Cytological studies were performed on 157 middle ear effusion specimens, 54 of which belonged to the serous and 103 to the mucoid category. The cytocentrifuged samples were stained with May-Gruenwald-Giemsa stain and divided into the three groups on the basis of cellular pattern: granulocytic, lymphocytic-monocytic and mixed. The T-lymphocytes were counted after incubation for six hours using alpha-naphtyl-acetate esterase (ANAE) marker and counterstaining with toluidine blue. In 57 samples, reliable assessment of lymphocytes could not be made because the absolute number of white blood cells was small or the lymphocytes were less than 100. In the remaining 40 serous and 60 mucoid samples, lymphocytes were present in sufficient numbers. The mean percentages of ANAE-positive lymphocytes were 62% serous and 57% mucoid. The results indicate that there is no numerical defect of the T-cells in chronic middle ear effusions.