Identification of Merkel Cells in the Labia Minora Skin of Prepubertal Girls

Aim: Merkel cells are located in glabrous skin, hairy skin, and in some mucosa. Clinically significant for their role in sensory perception, neuroendocrine signaling, and MC carcinoma of the vagina, the study of genital tissue sources may enhance understanding of sexual arousal, changes in sexual sensitivity in various hormonal environments, and perhaps even epithelial changes that precede cancer. Details about Merkel cell appearance, location, and function continue to emerge, but little is known about these details in female genital tissue.

Methods: Labial skin samples were obtained from ten normal girls (age 2-9 years) who underwent surgery. The specimens were waste tissue obtained at surgical intervention. All specimen were obtained by the senior investigator, a pediatric urologist, after informed consent had been obtain from the parent or legal guardian. Immunocytochemistry with double immunofluorescence against protein gene product (PGP) 9.5, and CK-20 was performed.

Results: Merkel cells were detected with Merkel cells identified as a single cell isolated near the basal lamina, grouped in the stratum spinosum of the epidermis, around the protrusion of a dermal papilla, or located in more superficial layers of the epidermis in close contact with the axon terminals of sensory nerve fibers. Merkel cells stain by fluorescence immunohistochemistry using antibodies for PGP 9.5 and CK-20.

Conclusion: Merkel cells are identified in the labial minora of prepubertal girls by colocalization with double immunofluorescent staining for PGP 9.5, and CK20.