‘Epidermotropism’ vs. ‘exocytosis’ of lymphocytes 101: definition of terms

The terms 'epidermotropism' and 'exocytosis' are commonly used to describe intraepithelial lymphocytes in the mycosis fungoides (MF) variant of cutaneous T cell lymphoma (CTCL). However, both terms have not been uniformly or consistently defined. In this study, definitions of both terms were requested from 34 experts. In definitions provided by 19 responders, 'epidermotropism' correlated with MF/CTCL, and 'exocytosis' correlated with benign conditions. Use of these terms often reflected the observer's interpretation, as they were not always used in purely descriptive fashion.