Merkel Cell Distribution in the Human Eyelid

Although Merkel cell carcinoma of the eyelid is reported frequently in the literature, only limited information exists about the distribution of Merkel cells in this tissue. Therefore, serial sections of 18 human cadaver eyelids (donors ages ranging between 63 and 97 years) were stained for cytokeratin 20 in various planes. The overall appearance of Merkel cells in these samples was low and mainly located in the outer root layer of the cilia hair follicles. Merkel cells were more frequent in the middle, and almost not detectable at the nasal and temporal edges. The localization is in accordance with that of Merkel cell carcinoma, but concerning the scarce appearance within this adulthood group, a specific physiological role of these cells in the eyelid is difficult to establish.