Interstitial Cajal-like cells in human uterus and fallopian tube

Recently, parallels have been drawn between enteric interstitial cells of Cajal (ICC) and similar cells outside the gut-interstitial Cajal-like cells (ICLC). This article reviews our laboratory findings on ICLC in the female reproductive tract. Since the morphology and function of ICLC are still a subject of debate, our purpose was to investigate whether ICLC are present in the fallopian tube and/or uterus, and if they share ultrastructural and immunohistochemical (IHC) features and/or functional roles. We studied ICLC presence in the human fallopian tube and myometrium primarily by light microscopy, and then by transmission electron microscopy (TEM), in tissue samples and at a single cell level. Taking advantage of our ICLC studies of several organs (pancreas, mammary gland, myocardium), we assembled a set of criteria, derived from ultrastructural features of ICLC, called "platinum standard." Besides the putative pacemaker function, ICLC might have other physiological roles, depending on tissue type (e.g., intercellular signaling, immune surveillance, steroid sensors). Consequently, there is a great urge for a conceptual framework that could allow a better understanding, from a functional point of view, and more so, as the ICLC processes are the longest cellular prolongations (except neurons).