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PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS IN T H E COAGULATING GLAND AND PROiSTATE O F T H E MOUSE HAROLD BURROWS, C.B.E. (From The Research Institute, The Cancer Hospital ( F r e e ) , London) Lacassagne, de Jongh, and Burrows and Kennaway have recorded the appearance of stratified, squamous, keratinixing epithelium in the prostates of mice which have undergone prolonged treatment with oestrin. Subsequent work by the author has shown that the organ characteristically affected in this way is the coagulating gland.' This Kctohydvoxyocrtrin. Ketomothoxyoestvin. III IV OH Tri hydvoxy- Equilrnin. oestvin. CHART I organ was commonly regarded as a part of the prostate until Walker in 1910 first discovered its separate nature and function. Further observations have now been made upon the effects produced by oestrin on the coagulating gland and prostate, and they appear worth consideration in connection with human pathology. Lesions have been brought about in the coagulating gland and prostate of the mouse by four closely allied oestrogenic substances, namely ketohydroxyoestrin, ketomethoxyoestrin, trihydroxyoestrin and equilin (Chart I). A fifth compound, equilenin, which is of somewhat similar structure, has 1 Acknowledgments are due to Professor Tom Hare, who first drew the author's attention to the coagulating gland. 2 The constitutional formula of equilin is not yet established. 490 PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 491 shown effects which suggest that it may be a link between the highly potent substances just named, and others which are inert. The completed experiments with this compound are too few to establish any final opinion as to its action. Only three post-mortem results are available, and in two of these cases, after 191 and 230 days of treatment respectively, no detectable changes in the prostate or coagulating gland are seen. I n the third mouse, which was killed on the 239th day of the experiment, there were a pronounced keratinization of a structure which the author regards as an uterus masculinus (p. 503) ; and possibly a slight stratification in the ducts of the coagulating gland, though this latter point is somewhat doubtful. The number of mice studied with each of the oestrogenic compounds is shown in Table I. TABLE I: Experimental Maleria2 Compound wed Ketohydroxyoestrin Ketomethoxyoestrin Equilin Trihydrox yoest,rin Equilenin TOTAL Number of mice 187 40 10 Number examined histologically a t date of writing (Sept. 21, 1934) 67 11 n a 5 1 10 4 252 86 All of the substances used have been chemically pure. I n the great majority of the experiments the compound to be tested, dissolved (0.1 or 0.01 per cent) in benzene o r alcohol, has been applied twice a week by means of a small paint brush to the non-epilated skin of the interscapular region. I n a few experiments oily solutions have been injected subcutaneously. Throughout the following account the term oestrin will indicate ketohydroxyoestrin, with which most of the experiments were done. The results hitherto obtained suggest that the compounds used a r e not all equally potent in producing lesions of the accessory genital organs. Several factors, however, have to be considered before a judgment on this point can be made with safety: differences of solubility of the materials in the media employed is one, and there are others. For this reason no attempt will be made in these notes to assess the comparative potencies of the various compounds employed. ANATOMY The prostate of the mouse has been described by Deanesly and Parkes as consisting of paired anterior, ventral and dorsal lobes with a single small median The structures included in this descrip3 Disselhorst specifies these “anterior” and “dorsal” lobes as the upper and lower portioiis of the posterior lobes, regarding the mouse for anatomical purposes as erect, while Deanesly and Parkes base their description on the animal in the prone position. 492 HAROLD BURROWS tion comprise two distinct organs which differ from each other in function and histological appearance. The lobe termed anterior by Deanesly and Parkes, which is closely attached to the seminal vesicle, is the coagulating gland (Figs. 1, 2 ) . I t s duct opens into the prostatic urethra close to the common ejaculatory ducts on the cranial side. The APPARATUS0% YOUNG ADULT MALE MOUSE FIG.1. VENTRAL ASPECT OF GENITO-URINARY Cg = Coagulating gland. C = Cowper ’8 gland. Pgl = Preputial gland. GO = Genital omenturn. VS = Seminal vesicle. B1= Bladder. P r = Prostate. I FIG.2. SECTION THROUQH ACCESSORY GENITALIAOF NORMALMALE MOUSE Cg = Coagulating gland. VS = Seminal vesicle. P r = Prostate. N B = Neck of bladder. The section is slightly oblique 80 that the seminal vesicle and coagulating gland are not completely shown 011 the right side. X 4. secretion of this gland causes coagulation of the contents of the seminal vesicle immediately after ejaculation, and thus produces the “copulation plug. ” Walker found that the secretion of the coagulating gland was not specific for each species: that of the guinea-pig, for example, being capable in extremely small amounts of causing coagula- PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 493 tion of the fluid secreted by the seminal vesicles of the rat. The contents of the prostate showed no such capacity. I n the following account the ventral, dorsal, and median lobes, in the terminology of Deaiiesly and Parkes, will be regarded a s the prostate as distinct from the coagulating gland. FIG. 3. SECTION THROUGH AN ALVEOLUSOF THE COAGULATING GLANDO F -4 NORMAL MOUSE. X 360 THROUGH ACCESSORY GENITALORGANSOF MOUSETREATED BY OESTRIN FIG.4. SECTION The coagulating glands on both sides have been converted into sacs (Cg) lined with keratinizing stratified epithelium. VS = Atrophic seminal vesicle. B1= Bladder. P r = Prostate. VD = Vas deferens. Mouse 835, 102d day. X 5. EFFECTS OF OESTRINO N THE COAGULATING GLANDS Under the continued administration to mice of sufficiently large doses of oestrin, the coagulating glands, the alveoli of which normally are lined by a single layer of cuboidal o r columnar epithelium (Fig. 3 ) , become converted into sacs lined by a squamous, stratified epithelium, the superficial layers of which, with time, undergo keratinization. I n some instances these sacs become filled with keratinized material alone, in others with masses of keratinized material together with desquamated nucleated and noii-nucleated epithelial cells, and polymorphonu- FIG. 5. SECTION THROUGH T HE W A L L OF A COAGULATING BY OESTRIN GLANDTO SHOW METAPLASIAINDUCED The sac is filled eiitirely with layers of keratinized material amongst which no iiucleated cells can be seen. The iiiiier surface of the wall of the sac faces t o the left. Mouse 800, 164th day. X 240. FIG. 6. SECTION THROUGH T H E W A L L OF A COAGULATING GLAND TO ILLUSTRATE POLYMORPHONUCLEAR INVASION AND SHEDDING OF THE SURFACE LAYERS OF STRATIFIED EPITHELIUM The contents o f the sac a r e masses of keratinized material, nucleated and iioii-nucleated epithelial cells, aiid leucocytes. Mouse 788, 155th day. X 240. 494 PATHOLOGICAL CONDITIONS I N D U C E D BY OESTROGENIC COMPOUNDS 495 clear leucocytes (Figs. 4, 5 , 6). The pouches so formed resemble in their microscopic structure of the vagina of the mouse, and they undergo changes which recall the cyclical phenomena of oestrus occurring in that organ. Thus the formation of a many-layered, stratified epithelium undergoing copious keratinization (Fig. 5 ) may be followed by a polymorphonuclear invasion of the epithelium the superficial layers of which are shed, leaving a lining of squamous epithelium denuded of horny cells and only three or four cells in thickness (Fig. 6). The metaplasia described above appears to be constant in its appearance. Though there may be, and almost certainly are, individual FIG.7. SECTION THROUGH PROSTATE OF NORMAL ADULTMOUSE. X 170 variations of susceptibility, every mouse hitherto examined after continued treatment with repeated doses of oestrin for three months o r longer has shown the characteristic metaplasia of the coagulating glands. EFFECTS OF OESTRINON THE PROSTATE, PROSTATIC URETHRA, AND PERIURETHRAL GLANDS The alveoli of the prostate in the normal mouse are lined by a single layer of cells arranged in an orderly manner and containing sufficient cytoplasm to make each nucleus appear isolated and distinct when examined in thin sections (Fig. 7). When stained with eosin and haemotoxylin, the cytoplasm takes a pale pinkish tinge, while the nuclei are purple and usually do not stain very deeply (Fig. 7). Under the continued administration of oestrin three alterations are induced. ( a ) In the early stages the orderly disposition gradually disappears so that the alveoli become lined by disarranged cells, which are no longer in a 496 HAROLD BURROWS single row. There appears t o have been proliferation of the cells, which in places lie in superimposed layers; and their nuclei-as the condition advances-are stained a deeper purple or blue and become crowded together owing to a diminished proportion of cytoplasm (Fig. 8). ( b ) Accompanying these epithelial changes is a gradual increase of the connective-tissue stroma of the gland (Fig. @). At this stage the condition resembles benign hyperplasia of the human prostate (Fig. 23). (c) Eventually a high grade of metaplasia occurs, the disordered epithelium of the ducts and alveoli being replaced by a stratified epithelium consisting of cells which are larger and more regular in shape and dimensions than those they have replaced. These stratified cells have relatively definite outlines ; their cytoplasm stains PIG. 8. SECTION THROUQH PROSTATE SHOWIKQ IIYPERPLASIA 03’ EPITHELIUM AND CONNECTIVE TISSUEINDUCED BY OESTRIN Mouse 856, 97th day. X 115. rather faintly, and their round or oval nuclei are vesicular and do not clearly show any structure (Fig. 9). This stratified epithelium in the prostate, unlike that which appears in the coagulating gland, has not been observed t o undergo keratinization. This difference may be one of degree only, f o r the metaplasia in the coagulating gland in its earlier phases passes through a non-keratinous stage resembling that just described as occurring as a late event in the prostate. A noteworthy feature of these transformations in the epithelium of the prostate is the sequence in which they develop in the different regions of the gland. The earliest changes are seen in the ducts and gradually spread from these foci toward the periphery, so that in some cases, while an advanced pathological condition may be observed in the ducts and proximal alveoli of the prostate, the peripheral regions may FIG.9. SECTION THROUGH PROSTATE SHOWING CONVERSION O F CELLS STRATIFIED EPITHELIUM LININGALVEOLI INT'0A Tlic:re is an increase of coniiective tissue also. Mouse 846, 312th day. X 170. Cf. Fig. 23. FIG.10. SECTION THROUGH PROSTATE SHOWING ADVANCED METAPLASIA( S T ) AND ALVEOLI OF A VENTRAL (ANTERIOR) LOBULE Ur = Prostatic urethra. Mouse 846, 312th day. 497 X 62. OF THE DU' CTS 498 HAROLD BURROWS appear to be little affected. Thus a stratified epithelium may be present i n the ducts and proximal alveoli and a pronounced hyperplasia in an intermediate zone, while the peripheral regions of the gland may appear almost normal. Although in the mouse, as in man, the greater part of the prostate arises by outgrowths from the dorsal wall of the urethra, so that the main ducts of the fully formed gland open in or near to the prostatic grooves on each side of the verumontanum, there are in addition two or more lobules which discharge through the ventral wall of the prostatic urethra. These ventral lobules, like those which constitute the FIG.11. LONGITUDIKAL ~ E C T I O N THROUGH TEE URETHRA DISTALTO THE COLLICULUSSDMINALIS, METAPLASIAOF THE EPITHELIUM OF THE DUCT O F A PERIURETHRAL GLAND The urethral epitlielium has a h undergone a change towards stratification. Mouse 860, 372d day. X 115. SHOWING main body of the gland, may exhibit metaplasia in response to the administration of oestrin (Fig. 10). Such changes caused by oestrin are not confined to the coagulating gIand and prostate. The periurethral glands of the prostatic urethra and their ducts may be similarly affected (Fig. ll),and the transitional epithelium of the prostatic urethra may become much thickened o r even converted into a stratified layer many cells in depth (Fig, 12). Eventually the columnar epithelium which lines the lower ends of the common ejaculatory ducts may be partially replaced by stratified epithelium. When it occurs, this replacement, as in the preceding instances, spreads in a well defined manner, the stratified epithelium first appearing at or near the mouths of the ducts, and extending gradually along their cranial walls; so that sections often will show the caudal FIG. 12. TRANSVERSE SECTION OF PROSTATIC URETHRA (Ur) SHOWING REPLACEMENT OF TRANSITIONAL EPITHELIUM BY A STRATIFIED EPITHELIUMMANY CELLS IN THICKNESS Mouse 869, 70th day of treatment by equiliii. X 60. FIG. 13. SQUAMOUS STRATIFIED EPITHELIUM(ON RIGHT) REPLACING THE NORMAL COLUMNAR CELLS(ON LEFT)WHICHLINE THE COMMON EJACULATORY DUCT Mouse 858, 104th day of treatment with oestrin. X 115. 499 500 HAROLD BURROWS part of the circumference of each duct with a normal lining of columnar cells, while the cranial part consists of a thick stratified layer (Fig. 13). EEVERSIBILITY OF THE EFFECTS OF OESTRIN A point of particular interest is that the alterations produced by oestrin in the prostatic urethra and the glandular structures connected therewith, including the coagulating gland, are reversible. If the ap- ORGANSOF TWO MICE, ILLUSTRATINQ REVERSIBILITY OF FIQ.14. GENITO-URINARY OESTRIN EFFECTS OF Both mice were treated alike with bi-weekly applications of oestrin for 168 days. For the next 42 days oestrin was applied to A as before, while B was untreated. I n the latter the return to their normal size of the seminal vesicles, Cowper '8 g l a d , testes, and genital omeiitum are shown. In B the coagulating gland has become translucent, while it is opaque in A. Mice 955 and 956. plications of oestrin be stopped, the d6bris of keratin and desquamated cells filling the distended alveoli of the coagulating gland disappears, and the alveoli become lined again with a single layer of cuboidal or columnar cells which now resume their normal aspect and function. Coincidentally with these restorative changes the gland ceases to retain the obvious form of a sac, its walls becoming again much plicated. Following the cessation of treatment with oestrin, the stratified epithelium disappears entirely from the prostate, also, the secretory cells of which are restored likewise to their proper appearance and activity (Figs. 14-16). I n every situation where a stratification of epithelium or a desquamative hyperplasia has appeared in response t o applications of oestrin it will give place, it seems, to the epithelium appropriate t o the normal tissue if the administration of oestrin be stopped. (A reversibility of effect is seen in an equally striking degree in the seminal vesicle, though the alterations produced by oestrin in this organ are of a different form from those seen in the coagulating gland and prostate and will not be included in the present discussion.) PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 501 This reversion to the normal state comes about in a definite succession, the more peripherally situated alveoli, which were the last to be affected, being the first to recover. Such a sequence is seen most clearly in the prostate, which returns t o its normal condition more rapidly than the coagulating gland. Although the gross epithelial transformations appear earlier in the coagulating gland, and involve the entire organ much more rapidly than the changes in the prostate, yet the peripheral alveoli of the coagulating gland are not affected quite so soon as the ducts and proximal alveoli. And again, during the re- FIG. 15. SECTION THROUGH THE PROSTATE OF TION GLANDS (Cg) AS MOUSEA (956) IN FIG.14, KERATINIZED SACS. x 4 SHOWING COAGULA- FIG.16. SECTION THROUGH THE PROSTATE OF MOUSE B (955) OP FIG. 14 The coagulation glands ( C g ) are lined with a single layer of columnar epithelium and contain secretion of normal appearance. The semiual vesicles (VS) also are distended with secretion. X 4. version to normal after the cessation of treatment with oestrin, a difference may be noticed between the recovery in the distal parts of the gland as compared with the proximal portions. Thus, during the process of recovery, a normal secreting epithelium may be visible at the peripheral end of a sac the proximal end of which is still lined by a stratified epithelium (Fig. li).* 4 Espinasse (Nature 134: 738, 1934) has called attention t o a similar gradient of reactivity to oestrin in the surviving remnants of the niiillerian ducts in the female, namely, the vagina, uterus, and oviducts. The effects of oestrin are most pronounced in the vagina and diminish in intensity along the uterus and toward the oviducts. 502 HAROLD BURROWS No easy explanation is forthcoming to account for this variation of the effect of oestrin on the different parts of the glands, inasmuch as the active substance is conveyed by the blood stream and therefore, it would seem, must reach in an equal concentration all the tissues concerned. Possibly the differences of susceptibility may be connected with the embryological origins of the tissues concerned. Lacassagne has suggested that the selective action of oestrin on the prostate of the mouse-using this term to include the coagulating gland-may indicate FIG.17. SECTION SHOWING SEQUENCE OF CHANGESDURING RECOVERY FROM THE EFFECTS OF GLAND then stopped. The mouse was killed the large sac of the coagulating glaiid a large keratinous mass ( K ) remains. which appear normal and this p a r t of O E S T R I N I N T H E COAGULATING Oestrin treatment was continued f o r 220 days and twenty-five days later. I n the proximal (lower) p a r t of which is shown, stratified epithelium ( S t ) is present and The distal portion ( A ) is lined by a single layer of cells the cavity is filled with secretion. Mouse 941. X 60. that this structure arises from Muller’s ducts. Wesson and also Arey have stated that a portion of the dorsal wall of the urethra adjacent to the ejaculatory ducts is derived from the wolffian ducts. It seems possible that the mullerian ducts might in a similar manner contribute to the formation, not only of the utriculus itself, but to a portion also of the contiguous part of the urethral wall from which the coagulating glands, and perhaps portions of the prostate also, are developed. It might be, perhaps, that in the male an actual remnant of the lower end of the mullerian duct would respond the most readily to oestrin inasmuch as the uterus and vagina, which react specifically to this hormone in the female. are derived directly from Miiller’s ducts. A further pos- PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 503 sibility might be that an organ developed as a secondary outgrowth from the mullerian duct would be somewhat slower in its response, and that the degree of response would gradually diminish in intensity with the remoteness of the tissue concerned from the point of its embryological origin. Whatever the explanation is, the fact may be one of importance in human pathology, for a similarly graduated distribution of hyperplasia seems to the author t o occur in benign enlargements of the prostate in man. FIG. 18. SECTION THROUGH T H E PROSTATIC U R E T H R A AND SURROUNDING STRUCTURES OF A MOUSEWHICH HADBEENTREATEDWITH OESTRIN FOR 153 DAYS Immediately above the two common ejaculatory ducts is a large sac (X) filled with keratinous material and shed cells. Cg = Coagulating gland. Ur z Prostatic urethra. The suggestion is made that this sac is a uterus masculiiius. Mouse 880. X 4. FIG.19. NAKED-EYE VIEW OF A S U ~ O S E UTERUS D MASCULINUS(X) JUST BEHIND THE URINARY BLADDER (Bl) WHICH IS SITUATED Mouse 886, 157th day. I n connection with the possibility that oestrin may act specifically on structures derived from the mullerian apparatus, the following two observations may be of interest: (1) I n several of the mice which have been treated with oestrin, though not in all, a median sac has been found on the dorsal aspect of the prostatic urethra between the distal ends of the vasa deferentia and projecting toward the peritoneal cavity immediately behind the urinary bladder (Figs. 18-20). The lower ends of the vasa deferentia are displaced by these sacs (Fig. 20) and the coagulating glands are closely associated with their lateral walls (Fig. 18). Such sacs, the largest hitherto observed being 13 x 13 x 10 mm., are lined by stratified keratinizing epithelium, and in some instances, like the uterus in the female after similar treatment with oestrin, are distended by clear fluid (Fig. 20). It seems probable that these structures represent the utriculus masculinus-an acknowledged relic of the miillerian apparatus-persistent in some individual mice only and rendered manifest 504 H A R O U ) BURROWS by the action of oestrin. Rauther, while admitting the existence of a utriculus masculinus in the new-born mouse, states that neither this nor any other remnant of the mullerian ducts is to be found in the fully grown mouse. This is contrary to Leuckart ’s observations ; and it is to be remembered that some inconstancy in their persistence and postnatal development is a recognised feature of many vestigial structures, and no generalisation as to their absence or survival in the adult can be made without the examination of a large number of individuals, F I G . 20. NAKED-EYE VIEW OF ANOTHERSUPPOSED UTERUSMASCULINUS( X ) The lower ends of the vasa defereiitia (VD) have been carried upward on each side of the sac. B1= Bladder. Mouse 976, 173d day of treatment with trihydroxyoestrin. ( 2 ) Becently, in a mouse which had been treated by oestrin for sixty-two days, an organ consisting of a number of tubules lined with squamous, stratified epithelium and completely filled with keratinous material, has been found connected with the epididymis, where vestiges of the cranial end of Miiller’s duct might be expected (cf. the sessile hydatid of Morgagni in man). A s measured in a microscope section the plane dimensions of this organ are 2 x 3 mm (Fig. 21). DISCUSSION When the foregoing observations are considered in connection with the pathology of prostatic lesions in man, certain questions arise. (1) Does a n y representative of the coagulating gland ezist i.n man8 This question may seem perhaps academic rather than clinical and practical. At present it remains unanswered. Walker, in the paper already quoted, states that he was unable t o find in man any representative of the coagulating gland, though he thought the coagulated particles found in human semen suggested the presence of such a gland. ( 2 ) C a n the benigm prostatic enlargements commonly found in elderly m e n be compared w i t h those which have been induced in mice by the administration of o e s t r i d ( a ) Anatomical distribution of the changes: Unfortunately the exact situation of lesions in the human prostate cannot be described ac5 Speaking of the water vole (Hypudaeus), Leuckart mentions a ‘ ‘maiiiiliche Scheide’ ’ consisting of a “blindsackformiger Recessus” and goes on to say that the structure in Mus musculus is quite similar (loc. cit. p. 259). PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 505 curately in the current anatomical phraseology. It is customary to refer to the various “ lobes ” of the prostate. But this gland is compact, and though developed by several groups of outgrowths from the prostatic urethra, the primitive lobules so formed soon become amalgamated, and are then for the most part no longer distinguishable to the naked eye and certainly have not the form of lobes. To this circumstance must be attributed the discrepancies which appear in the literature when pathological conditions are described as having arisen FIG.21. KERATINIZED STRTJCTURE ( Z ) ATTACHED TO THE EPIDIDYMIS (Ep) OF A MOUSEWHICH HAD BEEN TREATEDWITH OESTRINFOR 62 DAYS Testis ( T ) sliows absence of spermatozoa and spermocytes. VD z Vas deferens. Twelve days before any oestriii was applied the mouse had been rendered cryptorchid by dividing the gubernacula and displaciiig the testes into the abdomiiial cavity. Mouse 953. X 24. in this or that particular “lobe. ” Nevertheless, pathologists are likely to agree that hyperplasiat of the prostate shows little tendency to affect the posterior lobe, the embryological origin of which is situated distally to the utriculus. From general observation, unchecked by exact inquiry, it seems that the parts of the prostate which are subject t o the most pronounced degrees of hyperplasia in elderly men are the middle lobe and the cranial portions of the lateral lobes. It further appears that the hyperplasia in its most advancedform is seen especially in those 506 HAROLD BURROWS regions which lie nearest to the proximal part of the prostatic urethra itself. Thirty years ago Wallace expressed an opinion of this kind when pointing out that after so-called enucleation of an enlarged adenomatous prostate there is always left behind a definite laminated envelope containing glandular tissue derived from the expanded outer portion of the organ. Such a distribution is in conformity with that of the metaplasia noticed by Schlacta in the prostates of newborn babies (p. 510) and by the author in the coagulating glands and prostates of mice which have been subjected to prolonged treatment with oestrin. Riches and Muir examined 59 prostates removed at autopsy FIG. 22. NEWBORN CHILD STRATIFIED EPITHELIUM. X 170 Cf. Figs. 9 and 10. SECTION THROUGH THE PROSTATE OF A AT F U L L TERM, SHOWINa and showing benign hypertrophy. The regions which they found involved are as follows: Regiom Involved in 50 Cases of Benigla Hypertrophy of the Prostate (Riches and Nuir) Lateral lobes ....................................................... 90 per cent Middle lobe associated with lateral lobes ............................... 34 Middle lobe alone (all being early cases) ............................. 6 Anterior lobe ...................................................... 1 Posterior lobe, associated in every instance with changes in the lateral lobes., 6 ( b ) Resemblance between the histologic changes produced experiinentally in mice b y oestriul. a d those appearing in the human prostate: Two successive changes have been described above as occurring in the prostate of the mouse under the influence of oestrin, namely (1) a hyperplasia of the secreting epithelium together with an increase of the connective-tissue stroma, and ( 2 ) replacement of the cells lining the alveoli of the gland by a stratified epithelium. As remarked already, 0 hlbarran’s glaiids are included with the middle lobe here, PATHOLOGICAL CONDITIONS INDUCED BY OESTROOENIC COMPOUNDS 507 it may perhaps be correct to refer to these as different stages of a single process, the borderline between hyperplasia and metaplasia being difficult to define. However this may be, both changes are to be seen in the prostates of elderly men, though the appearance of stratified epithelium in these is relatively uncommon. The earlier o r hyperplastic changes which are commonly characteristic of benign enlargements of the human prostate (Fig. 23) closely resemble in essential details those seen in the prostate of the mouse which has been treated with oestrin. The less frequent condition in which stratified epithelium appears was first recorded in 1865 by Thiersch, whose observa- FIG.23. SECTIONTAKENFROM PROSTATIC TISSUEREMOVED FOR THE RELIEFOF A SUPPOSEDLY BENIGNE N L a R G E M E N T Stratification of the epithelium of the alveoli and ducts was fouiid in one place, the bulk of the material showiiig typical beiiigii hyperplasia. X 170. Cf. Figs. 9 aiid 10. tions were based on material removed from a patient with cancer. Since that time numerous pathologists have described the occurrence in the human prostate of stratified epithelium. Thus it will be seen that, so far as histological changes are comparable between mouse and man, there appears to be no essential difference between the enlarged prostates of elderly men and the prostates of mice which have been submitted to long continued dosage with oestrin. The similarity extends further, for the morbid consequences are almost identical; the majority of the affected mice, if the administration of oestrin be continued, eventually succumb t o urinary obstruction with distension and occasionally sacculation of the bladder, constant dribbling of urine from overflow, dilatation of the ureters, and hydronephrosis. Some of the mice die from abscesses arising in the coagulating gland. Here it may be mentioned that a common sequel to keratinisation 508 HAROLD BURROWS of the coagulating gland is a polymorphonuclear invasion of the epithelium (Fig. 6). This invasion takes place simultaneously over a wide area and can hardly be attributed t o infection. A similar phenomenon is recognized as a regular feature of the oestrus cycle in the vagina of the mouse, and the appearance of leucocytes in a vaginal smear from this animal is accepted as a proof that the period of oestrus has terminated. The matter is one of physiological interest, and may be considered in yet another condition, namely vitamin A deficiency. I n this condition, as shown by Wolbach and Howe, a wide-spread keratinization of epithelium occurs in various organs. This process is often accompanied by suppuration which has been attributed hypothetically to an increased susceptibility t o infection, or t o an absence of ciliated epithelium. It is possible that masses of desquamated, keratinized cells may offer a suitable nidus f o r some bacteria, and these may be present by chance in the blood and may be extravasated like the leucocytes and so cause an abscess as a secondary event. But the leucocytic invasion, as induced in the keratinized coagulating gland and vagina by oestrin, is almost certainly not the direct outcome of any bacterial action. (3) Do oestrogenic hormones play aizy part in the causation of beiiiyz edargenzeuzts of the prostate in man? ( a ) T h e presmce of oestrogewic hormones ijn males: Oestrogenic substances have been found in the blood, testes, and urine of men by 6sterreicher and by other enquirers. Although the amounts found by them are small, the quantities produced in the system might be sufficient, if continuously produced over many years, to bring about effects which would require much greater dosages if these were supplied only at intervals, as in the experiments on mice described above. But the whole subject of the detection and estimation of small amounts of oestrin in urinc requires further investigation. Zondek has shown that very large amounts of oestrin injected into young rats are rapidly inactivated or destroyed, and Frank and Goldberger have observed the same phenomenon in rabbits. It is known that a given dose of oestrin injected into an animal shows a more pronounced result if given in separate fractions with intervals of time between administrations, than if administered all at once. The changes induced by oestrin in the prostates of mice have not required enormous dosage. Each bi-weekly application (p. 491) of a solution of 0.01 per cent of oestrin contains about 3 micrograms of oestrin or 30 international units, so that 60 units were given in the course of a week. No calculation can be made of the proportion of this dosage which became absorbed. The quantities mentioned represent the maxima theoretically available. Such amounts constantly produced advanced changes in the mouse’s prostate. It seems reasonable t o suspect that a very much smaller quantity, if supplied continuously, would be enough to cause pathological changes in some of the individuals so treated. From these considerations there appears to be no valid objection, based on known facts, to the hypothesis PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 509 that prostatic enlargements in elderly men are brought about by the action of oestrogenic hormones. ( b ) D i w c t e v i d m c e that prostatic citlargemewt may be brought about in the human species by the action of ocstrifi: The information most desired on this problem, so f a r as it coiicerns men of advanced years, is not yet available, for the accumulation of data in present circumstances is slow. The need is t o ascertain whether the subjects of prostatic enlargement are or have been under the influence of exceptionally large quantities of the hormone concerned. It may be that in these individuals oestrin or a related substance is produced in excessive quantities or that its inactivation is retarded. But the hormone is effective in very small amounts and biological assay is in practice the only test available. Isolated aiid occasional estimations of the output in the urine of individual patients in these circumstances are laborious and not entirely satisfactory. A great number of observations will be necessary to establish a reliable conclusion. Nevertheless, there is evidence already at hand that the human prostate reacts t o oestrogenic hormones in the same manner as that of the mouse. The prostate of the human male child is, like the mamma, considerably enlarged at birth, diminishing in size during the first few weeks of extrauteririe life. I n women oestrin is produced in large quantity during pregnancy, and enters the foetal circulation. Philipp examined the urine of 24 newborn babies and constantly found oestrin present during the first three days after birth. By the sixth postnatal day oestrin had disappeared from the urine. Siegert and Schmidt-Neumann took blood from the umbilical veins of 26 newborn babies, and the sera from these samples yielded positive tests f o r oestrin in 19 instances. As early as 1894 Aschoff had demonstrated the presence of stratified epithelium in the utriculus masculinus, prostate, and periurethral glands of the newborn child. Teii years later IIalban, as the result of clinical and pathological observations, s u g p t e d that the peculiar conditioiis present in the mamma arid urogenital organs of newborn children were attributahle t o hormones derived from the mother. Schlacta, a t about the same time, studied the prostatic conditions present not only in the newborn, but in the foetus, and in infants up t o six months old. The results of his inquiry, published with illustrations iii 1904, are of great interest, which is not lessened by the fact that, like lialban’s deductions, they were made at a date prior to the identification of any of the sex hormones. Schlacta found epithelial changes in the prostate, utriculus masculinus, and urethra, beginning in the utriculus. Early in the eighth month of gestation, the normal epithelium of the prostatic ducts was becoming replaced by a stratified epithelium undergoing desquamation. I n the prostate itself only the “upper lobe” and the upper portions of the anterior part of the gland were affected. The change was symmetrical, and where the metaplasia was most marked there was a retardation of development of 510 HAROLD BURROWS the growing glandular buds. The stratified epithelium contained a considerable amount of glycogen. I n further investigations Schlacta found no trace of stratified epithelium in the prostates of foetuses at the beginning of the seventh month, though this was present in the utriculus masculinus at this time. I n the eighth month the prostate showed abundant stratified epithelium, and five newborn babies all showed the condition in a pronounced form. Prostatic metaplasia was‘ still to be seen in a baby of two months, but was absent from infants of four months and eleven months. These observations of Schlacta on the appearance and disappearance of prostatic metaplasia in the newborn are in perfect accord with those which have been made recently in the laboratory following the administration of oestrin to mice, and both sets of changes might be attributed to a similar agency. The characteristic condition found in the prostate of a newborn child is shown in Fig. 22. Occasionally in newborn male babies there is difficulty in urination owing to distension of the utriculus. Possibly this transient condition may be explained as the consequence of a response of the utriculus to the copious dosage with oestrin to which the foetus is submitted in the later stages of its sojourn in the uterus, and may be compared with that which has been described already as occurring in certain mice which had been treated with oestrin (Figs. 18-20). (4) Does oestrivt play a part in the causation of prostatic cancer? Experimentally there is no direct evidence in favour of an affirmative answer to this question. Carcinoma of the prostate has not been induced in mice by oestrin. Nevertheless, there are facts which demand reflection before such a query can be finally dismissed. I n human pathology Cheatle and Wale have called attention to the resemblance under the microscope between sections of prostates removed for nonmalignant enlargement in man, and sections of mammae affected with cystic desquamative hyperplasia or Schimmelbusch’s disease-or, in the old terminology, chronic cystic mastitis. And it is an interesting fact that oestrin brings about in mice a similar condition of desquamative hyperplasia not only in the prostate but in the mamma also. I n the latter situation this condition induced by oestrin is sometimes followed by cancer, even in males (Goormaghtigh, Lacassagne (1)). At the Royal College of Surgeons of England, in July, the author showed an example of mammary cancer with metastases in the lungs and elsewhere, which had developed in a castrated male mouse after the prolonged administration of oestrin. I n view of the fact that oestrin may cause desquamative hyperplasia in both the mamma and the prostate, and that the condition in the mamma is apt to be associated with cancer both in the human species and in mice, it is difficult to avoid the suspicion that oestrin or an allied substance may be one of the factors in the induction of cancer of the prostate. PATHOLOGICAL CONDITIONS INDUCED BY OESTROGENIC COMPOUNDS 511 CONCLUSIONS The prolonged administration of oestrin to mice causes hyperplasia and metaplasia in the prostate gland. The prostates of children before birth undergo similar changes, presumably under the influence of oestrin derived from the placenta. ‘ Both in mice and newborn children, the prostatic changes thus induced are completely reversible ; restitution to the normal state following a cessation of the supply of oestrin. The changes found in benign enlargement of the human prostate in advanced life resemble in character and situation those observed in mice under the influence of oestrin and in newborn babies. The question is discussed whether the benign enlargement of the prostate in elderly men may be due to the action of oestrogenic hormones and may be a reversible condition. NOTE: The author is much indebted to Sir G. Lenthal Cheatle, who placed a t his disposal a large collection of complete sections of human prostates showing pathological changes. For the supplies of oestrin, equilin and equilenin used in these experiments he is entirely indebted to the kindness and generosity of Dr. Girard. The ketomethoxyoestrin was prepared in this Institute by Dr. Cook, and to him also grateful acknowledgment is expressed. REFERENCES AREY,L. B.: Developmental Anatomy, W. B. Saunders Co., Philadelphia, 1930, p. 225. ASCHOFF, 1,. : Ein Beitrag zur normalen und pathologischen Anatomie der Schleimhaut der Harnwege und ihrer driisigen Anhange, Virchows Arch. f . path. Anat. 138 : 119, 1894. BLmmws, H., AND KENNAWAY, N. M.: On some effects produced by applying oestrin to the skin of mice, Am. J. Cancer 20: 48, 1934. CHEATLE,SIR G. LENTHAL,AND WALE,R. S.: A lesion common to breast and prostate glands, Brit. J. Surg. 17: 619, 1930. R., AND PARKES, A. S. : Size changes in the seminal vesicle of the mouse during DEANESLY, development and after castration, J. Physiol. 78: 442, 1933. DE JONGH, S. E. : Gcschlechtshormone und Schleimhautabstossung im mannlichen Genitalapparat, Acta Brevia Neerl. 3: 112, 1933. DISSELHORST, R. : Ausfiihrappnrat und Anhangsdriisen der miinnlichen Gesohlechtsorgane, Lehrbuch der vergl. mikros. Anat. der Wirbeltiere, 1904, pt. IV, G. Fischer, Jena. FRANK, R. T., GOLDEERGER, M. A., A N D SPIELMAN, F.: Present endocrine diagnosis and therapy; a critical analysis based on hormone studies in the female, J. A. M. A. 103: 393, 1934. GOORMAGHTIGH, N., AND AMERLINCK, A. : Realisation experimentale de la maladie de Reclus de la mamelle chez la souris, Bull. Assoc. franc. p. 1’Btude du cancer 1 9 : 527, 1930. LACASSAGNE, A.: (1)Apparition de cancers de la mamelle chez la souris mlle, soumise ti des injections de folliculine, Compt. rend. de 1’Acad. d. sci. 195: 630, 1932. LACASSAGNE, A. : ( 2 ) MQtaplasie epidermoide de la prostate provoquQe, chez la Souris, par des injections rQp6tees de fortes doses de folliculine, Compt. rend. SOC.de biol. 113: 590, 1933. R. : Zur Morphologie und Anatomie der Geschlechtsorgane, Gottingen Studien, LEUCKART, 1847, p. 259. GSTERREICHER, W. : Die Aussoheidung von Folliculin und Prolan bei lilteren und alten Miinnern, Klin. Wchnschr. 1 3 : 1019, 1934. 512 HAROLD BURROWS PHILIPP,E. : Sexualhormone, Placenta und Neugeborenes, Zentralbl. f . Ctynak. 53 : 2386, 1929. RAUTHER,M. : fiber den Genitalapparat einiger Nager und Insectivoren, insbesondere die akzcssorischen Genitaldriisen derselben, Jenaische Ztschr. f . Naturwiss. 38 : 377, 1904. RICHES,E. W., AND MKJIR, E. G.: The relationship of the structure of the enlarged prostate to the end results of prostatectomy, Brit. J. Surg. 20 : 366, 1933. SCHLACTA, J. : Beitrage mr mikroskopischen Anatomie der Prostate und Mamma des Neugeborenen, Arch. f . mikr. Anat. 64: 405, 1904. SIEGERT, F., AND SCHMIDT-NEUMANN : Der Hormonspiegel in mutterlichen und kindlichen Blut am Ende der Schwangerschaft, Zentralhl. f . Gynak. 54: 1630, 1930. THIERSCH, C. : Der Epithelialkrebs namentlich der Haut, W. Engelmann, Leipzig, 1865. WALLACE, C. S.: An anatomical criticism of the procedure known as total prostatectomy, Trans. Path. Soc. London 55: 255, 1904. WALKER, G. : A special function discovered in a glandular structure hitherto supposed to form a part of the prostate gland in rats and guinea-pigs, Johns Hopkins Hosp. Bull. 21: 182.1910. WESSON,M. €3. : Anatomical, embryological and physiological studies of the trigone and neck of the bladder, J. Urol. 4 : 279, 1920. WOLRACH, S. B., AND HOWE,P. R.: Tissue changes following deprivation of fat-soluble A vitamin, J. Expcr. Med. 42: 753, 1925. WOLBACH, S. B., AND HOWE,1’. R.: Vitamin A deficiency in the guinea-pig, Arch. Path. & Lab. Med. 5 : 239, 1928. ZONDEK, B. : The fate of follicular hormone in the living. body, Lancet 2 : 356, 1934.