Cyclical and other variations in the tubal epithelium

Abstract While the tubal mucosa does not participate in the bleeding of the menstrual process, its epithelium exhibits a definite cyclical change comparable with that of the endometrium. It is, however, not nearly so conspicuous as the latter, being concerned more with microscopic changes in the cells rather than with the grosser changes in pattern seen in the endometrium. The present study, based upon the careful examination of the tubes, from 136 cases, in almost all of which the endometrium was also available for study, has demonstrated the following chief facts: 1. 1. The tubal epithelium consists of two chief types of cells, the ciliated and the nonciliated. The latter are often spoken of as “secretory” cells. A third type, the “peg” cells (“Stiftchenzellen,” “Schaltzellen”) are also described, but it is probable that these represent only a phase of the nonciliated cells. 2. 2. In the interval phase, the epithelium is uniformly tall, the ciliated cells being broad, with rounded nuclei near the free margin, while the nonciliated cells are rather narrower, the nuclei being more deeply placed and taking a deeper stain. 3. 3. In the premenstrual phase the ciliated cells become lower, so that the “secretory” cells project beyond them, giving the epithelial margin a ragged, uneven appearance. The “secretory” cells show a bulbous herniation into the lumen of the tube, often carrying the nucleus with it. This extrusion of nuclei is similar to that seen in many lower animals, but its significance is not known. In spite of the great loss of cells, mitoses are rarely seen in the tubal epithelium. 4. 4. During the stage of menstruation, the premenstrual changes are carried further, the epithelium becoming quite low. The ciliated cells, especially, remain broad and low, but the secretory cells also, having been emptied of their cytoplasm, are much lessened in height, the nuclei often being quite bare of cytoplasm. “Peg” cells are numerous, their appearance and distribution suggesting that they are merely emptied “secretory” cells. 5. 5. The postmenstrual phase is characterized first by a low epithelium, which quite rapidly, however, increases in height, so that by the third or fourth day after menstruation it is often almost as tall as during the interval phase. The cells are narrow, closely placed, and, after the first day or so, of uniform height. 6. 6. During pregnancy, the epithelium becomes even lower than in the menstrual stage, and in the later stages it may become almost flat in many places. Secretory changes are not seen at this time. 7. 7. Cilia can be demonstrated in all stages, especially through the examination of fresh tissues, by the technic described in the paper. They are also found in the tubal epithelium of young children and in women many years beyond the menopause. This suggests that they must have some other function than that of assisting in the propulsion of the ovum. Perhaps, as has been suggested by Hartman. their chief role may be that of keeping the tubal lumen cleansed of foreign particles of any kind. 8. 8. Efforts at differential staining of the secretion have thus far been unsuccessful. Neither glycogen nor mucin can be demonstrated, unlike the findings in the secreting endometrium. The various views as to the significance of this tubal secretion are discussed in the paper, although there is as yet no positive knowledge as to this point. 9. 9. The prepuberal tubal epithelium is rather low, but shows both chief types of cells. Cilia, however, are very sparse, and are usually not seen at all in fetal or very early postnatal life. 10. 10. The epithelium of the postmenopausal tube may remain quite high for a surprisingly long time, perhaps a number of years after the cessation of menstruation. Cilia, likewise, may persist for many years. Sooner or later, however, the tubal folds become rounded, of fibrous appearance, the epithelium becomes low or even quite flat, and cilia, of course, disappear. 11. 11. The tubal epithelium of tubes removed from patients suffering with hyperplasia of the endometrium was studied because the latter condition is unquestionably associated with a functional disturbance of the ovaries. Characteristically the epithelium was found to be high, uniform, compact, with narrow cells, most of which were ciliated. There was no evidence of secretory change. This bears out the view, for which there is other evidence, that the functional disturbance consists of an excess or persistence of the follicle stimulus, with an absence of the corpus luteum influence. 12. 12. The comparison of the tubal cycle in women with that of the lower animals, like the comparative study of the uterine and ovarian cycles, emphasizes the important differences, chronologic and histologic, which exist. For example, the estrus tube of the rodent resembles, not the menstrual or premenstrual tube of the human, but the interval phase. Since estrus in the lower type is undoubtedly due to the follicle hormone, it seems clear that in the human the maximum of follicle influence is reached during the interval phase, and that the later changes are due to the corpus luteum influence. To bear this out, the picture in the animal tube which resembles the human premenstrual tube is that seen in the metoestrum, during which stage the corpus luteum apparently plays the dominating role.