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Development of Prostate: Anatomical and Histological Studies1
DEVELOPMENT OF PROSTATE: ANATOMICAL AND AND HISTOLOGICAL STUDIES 1 R. E.
VAN
DUZEN, W.W. LOONEY
AND
C. N. DUNCAN
From Departments of Anatomy, Histology and Urology, Baylor University, Dallas, Texas
In 1934, we presented a paper entitled The Anatomy of the Prostate and Vesical Neck. We were criticised because we presented no microscopic studies to support our conclusions made from gross specimens. In this paper we wish to present microscopic studies from the vesical neck of patients of various ages. We have varied our studies in that we have made radial rather than cross or sagittal sections. We have found that sections made at "4 and 8 o'clock on the dial" are the most instructive. By this method we may follow the gland tubule from the urethra outward to the periphery and note the branching similar to the branching of a tree. This is best shown in the gross specimens but by making serial sections we may also follow the course of the ducts. In this paper we will not discuss the gross anatomy but refer the reader to the previous paper. Case 1, patient aged 4 years. In this specimen (fig. 1) the muscular tissue is the predominant element. We are able to follow fibers of the longitudinal muscle layer of the bladder down between the prostatic glands. We see no semblance of a septum, muscular or fibrous, in any of the sections. We do note a fibrous layer external to the bladder muscles which continues around the prostate to the region of the external sphincter. It shows no tendency to separate the bladder musculature from the prostatic glands. This is the extension of the pelvic fascia. In this specimen (fig. 2) we note the glandular structure. The ducts are not dilated. They are lined by a single layer of columnar epithelium. The acini are uniform in size and show little or no attempt at forming papilla such as are seen in later specimens. The muscular septa are continuous with the longitudinal muscle fibers of the bladder. They make up a great part of the prostatic mass. Case 2, patient aged 16 years, single. In this specimen (fig. 3) we note the glands have become racemose and the acini show a tendency to papilla formation. Please note that all acini are about the same size. 1 Read before annual meeting, American Urological Association, Quebec, Canada, June 29, 1938. . 473
474
VAN DUZEN, LOONEY AND DUNCAN
The muscular structure is partially replaced by glandular tissue. In figure 4 we note a slight tendency to formation of papilla in the acini. Case 3, patient aged 26 years, married. In figures 5 and 6 one sees a marked increase in the acini and the muscular structure consists of thin septa. We also note the extensive formation of corpora amylacea.
FIG. 1
FIG. 2
However these are reported in children of 4 years and do not necessarily , mean glandular activity. We do want to call your attention to the peripheral glands of the posterior lobe. Here we see vacuolization and and dilatation. What does that mean in a man of 26? We do not see any change in the epithelial lining of these acini. There is no evidence
475
DEVELOPMENT OF PROSTATE
of infection. Is this evidence of stasis or obstruction? Is this due to exhaustion and atony of the muscular structure in this area? Case 4. This is a cadaver specimen (figs. 7 and 8) and we have no history. We would judge it to be from a man of middle life. In this specimen we have more marked dilatation of the peripheral acini and marked dilatation of the ducts. \Ve also sec many acini filled with cellular debris and pus cells. But the dilated acini do not contain the
FrG. 3
F1G. 4
cellular debris even though the adjacent undilated acini are filled. To us this is suggestive that the dilatation is not the end result of infection, obstruction of the duct and dilatation of the terminal acini. It is strongly suggestive we must look elsewhere for the cause. We wish to call attention to the fact that the central acini are chiefly the ones that are infected. We also wish to point out that the infected acini show no attempt at papillary proliferation or spheroid formation.
476
VAN DUZEN, LOONEY AND DUNCAN
Case 6, patient aged 56, married. In this specimen (figs. 9, 10 and 11) we see both the dilatation of the peripheral acini and in 2 areas definite spheroid formation. These spheroids are in the central portion of the glandular structure rather than the periphery. In figure 10 we notice definite papillary proliferation and increase in connective tissue. The epithelium lining the acini is several layers deep rather than a single
FrG. 5
FIG. 6
columnar layer and there is evidence of mononuclear infiltration of stroma: These are all evidences of early hypertrophy. Figure 11 is taken from an area of dilated acini. We note none of the phenomena here that are seen in the spheroid. Cases 7 and 8. These are cadaver specimens (figs. 12 and 13) which show more marked spheroid formation but we see also the dilated peripheral acini. In 1 area in a spheroid we see vacuolization but not the dilated acini before mentioned.
DEVELOPMENT OF PROSTATE
477
In this study we have shown specimens from what we consider the most important epochs in the prostatic life of man. We have studied the
FrG. 7
FIG. 8
embryo but because this subject has been so well covered by Doctor Lowsley we will not repeat it here. We believe that the prostate is the glandular portion of the bladder neck and not a separate anatomical structure. We find no septum fibrous
478
VAN DUZEN, LOONEY AND DUNCAN
FIG. 9
Frn.10
Frn.11
DEVELOPMENT OF PROSTATE
479
or muscular which we would interpret as a capsule of the prostate. There is a fibrous layer on the external wall of the bladder which continues down over the prostrate but this is only the continuation of the pelvic fascia and it makes no attempt at separating the bladder from the prostate. We suspect this idea arose from examining cases of hypertrophy in whom pressure atrophy has taken place and produced a pseudocapsule.
FIG. 12
FIG. 13
We are not entirely in agreement with Lowsley as to the division of the prostate into lobes in the embryo. It is very probable that pressure from the repeated contractions of the trigon muscle on the floor of the prostatic urethra plays a large role in the later division of the prostatic areas into the so-called lobes. Writers in the past have tried to make the prostate too complex a structure. We have noted the glands of the so-called posterior lobe develop more rapidly than other parts of the
480
VAN DUZEN, LOONEY AND DUNCAN
prostate. This gives rise to the appearance of appendages posterior to the vasa in the young adult. Later the lateral lobe develops and this is less marked. About the time we begin to notice spheroid formation we also note that the glands of the median lobe are increasing in size. This is better shown in the sagittal sections. We are very much interested in the significance of the dilated peripheral acini. We notice their appearance in specimens of early sexual life. These continue to be present after the spheroids appear. Are they evidence of retention? We frequently note dilated ducts leading to them. But we have been unable to find any periductal thickening which would cause obstruction. Do they represent a loss of ability of the muscles about the acini to completely empty these acini? We are aware that the ejaculation is more forceful in the young male than in one of middle life. When we massage the prostate, we frequently notice a crackling sensation just beneath the rectal mucosa suggesting the breaking of cysts. We suspect it is the emptying of these dilated acini that we feel. It is very suggestive that prostatic massage would benefit cases with marked dilatation of peripheral acini. It may be the explanation why Grant is able to report good results from intraprostatic injection because he has learned to inject into these dilated peripheral glands and others attempt to inject deeper. What do the spheroids represent? It is seldom we see dilated acini in the area that spheroids develop. It is very improbable they are the result of irritation from retained prostatic secretion, as some have suggested. If that were true, we should see them in the periphery where retention is more pronounced. Serralach produced in dogs the connective tissue reaction seen in hypertrophy by repeated and frequent masturbation. But spheroids are seen at the time of life when the sexual activity usually becomes less frequent. However it must be admitted that attempts at frequent intercourse in men late in life, as an old man marrying a young active mate, usually induces prompt prostatic hypertrophy. Our attention was called to the similarity of the spheroids in the prostate and the lobular type of breast hyperplasia known as mazoplasia or adenosis. Mazer states the latter are due to hyperfunction of the anterior pituitary gland. Our fellow member Doctor Lower has shown in animals that injection of anterior pituitary extract will increase the size of the prostate and that testicular hormone will cause regression. Is it not possible they are similar in origin? We only offer this as a sug-
DEVELOPMENT O:F PROSTATE
481
gestion and realize that much work is necessary before definite conclusions may be drawn. CONCLUSIONS
The prostate is not a separate anatomical organ but the glandular portion of the bladder neck. There is no capsule dividing the bladder from the prostate. We see dilatation of peripheral acini which are not related to hypertrophy. Spheroids appear in the prostatic tissue in middle age and there is suggestive but not conclusive evidence that this is endocrine in origin. Medical Arts Bldg., Dallas, Texas.
VAN
DUZEN, W.W. LOONEY
AND
C. N. DUNCAN
From Departments of Anatomy, Histology and Urology, Baylor University, Dallas, Texas
In 1934, we presented a paper entitled The Anatomy of the Prostate and Vesical Neck. We were criticised because we presented no microscopic studies to support our conclusions made from gross specimens. In this paper we wish to present microscopic studies from the vesical neck of patients of various ages. We have varied our studies in that we have made radial rather than cross or sagittal sections. We have found that sections made at "4 and 8 o'clock on the dial" are the most instructive. By this method we may follow the gland tubule from the urethra outward to the periphery and note the branching similar to the branching of a tree. This is best shown in the gross specimens but by making serial sections we may also follow the course of the ducts. In this paper we will not discuss the gross anatomy but refer the reader to the previous paper. Case 1, patient aged 4 years. In this specimen (fig. 1) the muscular tissue is the predominant element. We are able to follow fibers of the longitudinal muscle layer of the bladder down between the prostatic glands. We see no semblance of a septum, muscular or fibrous, in any of the sections. We do note a fibrous layer external to the bladder muscles which continues around the prostate to the region of the external sphincter. It shows no tendency to separate the bladder musculature from the prostatic glands. This is the extension of the pelvic fascia. In this specimen (fig. 2) we note the glandular structure. The ducts are not dilated. They are lined by a single layer of columnar epithelium. The acini are uniform in size and show little or no attempt at forming papilla such as are seen in later specimens. The muscular septa are continuous with the longitudinal muscle fibers of the bladder. They make up a great part of the prostatic mass. Case 2, patient aged 16 years, single. In this specimen (fig. 3) we note the glands have become racemose and the acini show a tendency to papilla formation. Please note that all acini are about the same size. 1 Read before annual meeting, American Urological Association, Quebec, Canada, June 29, 1938. . 473
474
VAN DUZEN, LOONEY AND DUNCAN
The muscular structure is partially replaced by glandular tissue. In figure 4 we note a slight tendency to formation of papilla in the acini. Case 3, patient aged 26 years, married. In figures 5 and 6 one sees a marked increase in the acini and the muscular structure consists of thin septa. We also note the extensive formation of corpora amylacea.
FIG. 1
FIG. 2
However these are reported in children of 4 years and do not necessarily , mean glandular activity. We do want to call your attention to the peripheral glands of the posterior lobe. Here we see vacuolization and and dilatation. What does that mean in a man of 26? We do not see any change in the epithelial lining of these acini. There is no evidence
475
DEVELOPMENT OF PROSTATE
of infection. Is this evidence of stasis or obstruction? Is this due to exhaustion and atony of the muscular structure in this area? Case 4. This is a cadaver specimen (figs. 7 and 8) and we have no history. We would judge it to be from a man of middle life. In this specimen we have more marked dilatation of the peripheral acini and marked dilatation of the ducts. \Ve also sec many acini filled with cellular debris and pus cells. But the dilated acini do not contain the
FrG. 3
F1G. 4
cellular debris even though the adjacent undilated acini are filled. To us this is suggestive that the dilatation is not the end result of infection, obstruction of the duct and dilatation of the terminal acini. It is strongly suggestive we must look elsewhere for the cause. We wish to call attention to the fact that the central acini are chiefly the ones that are infected. We also wish to point out that the infected acini show no attempt at papillary proliferation or spheroid formation.
476
VAN DUZEN, LOONEY AND DUNCAN
Case 6, patient aged 56, married. In this specimen (figs. 9, 10 and 11) we see both the dilatation of the peripheral acini and in 2 areas definite spheroid formation. These spheroids are in the central portion of the glandular structure rather than the periphery. In figure 10 we notice definite papillary proliferation and increase in connective tissue. The epithelium lining the acini is several layers deep rather than a single
FrG. 5
FIG. 6
columnar layer and there is evidence of mononuclear infiltration of stroma: These are all evidences of early hypertrophy. Figure 11 is taken from an area of dilated acini. We note none of the phenomena here that are seen in the spheroid. Cases 7 and 8. These are cadaver specimens (figs. 12 and 13) which show more marked spheroid formation but we see also the dilated peripheral acini. In 1 area in a spheroid we see vacuolization but not the dilated acini before mentioned.
DEVELOPMENT OF PROSTATE
477
In this study we have shown specimens from what we consider the most important epochs in the prostatic life of man. We have studied the
FrG. 7
FIG. 8
embryo but because this subject has been so well covered by Doctor Lowsley we will not repeat it here. We believe that the prostate is the glandular portion of the bladder neck and not a separate anatomical structure. We find no septum fibrous
478
VAN DUZEN, LOONEY AND DUNCAN
FIG. 9
Frn.10
Frn.11
DEVELOPMENT OF PROSTATE
479
or muscular which we would interpret as a capsule of the prostate. There is a fibrous layer on the external wall of the bladder which continues down over the prostrate but this is only the continuation of the pelvic fascia and it makes no attempt at separating the bladder from the prostate. We suspect this idea arose from examining cases of hypertrophy in whom pressure atrophy has taken place and produced a pseudocapsule.
FIG. 12
FIG. 13
We are not entirely in agreement with Lowsley as to the division of the prostate into lobes in the embryo. It is very probable that pressure from the repeated contractions of the trigon muscle on the floor of the prostatic urethra plays a large role in the later division of the prostatic areas into the so-called lobes. Writers in the past have tried to make the prostate too complex a structure. We have noted the glands of the so-called posterior lobe develop more rapidly than other parts of the
480
VAN DUZEN, LOONEY AND DUNCAN
prostate. This gives rise to the appearance of appendages posterior to the vasa in the young adult. Later the lateral lobe develops and this is less marked. About the time we begin to notice spheroid formation we also note that the glands of the median lobe are increasing in size. This is better shown in the sagittal sections. We are very much interested in the significance of the dilated peripheral acini. We notice their appearance in specimens of early sexual life. These continue to be present after the spheroids appear. Are they evidence of retention? We frequently note dilated ducts leading to them. But we have been unable to find any periductal thickening which would cause obstruction. Do they represent a loss of ability of the muscles about the acini to completely empty these acini? We are aware that the ejaculation is more forceful in the young male than in one of middle life. When we massage the prostate, we frequently notice a crackling sensation just beneath the rectal mucosa suggesting the breaking of cysts. We suspect it is the emptying of these dilated acini that we feel. It is very suggestive that prostatic massage would benefit cases with marked dilatation of peripheral acini. It may be the explanation why Grant is able to report good results from intraprostatic injection because he has learned to inject into these dilated peripheral glands and others attempt to inject deeper. What do the spheroids represent? It is seldom we see dilated acini in the area that spheroids develop. It is very improbable they are the result of irritation from retained prostatic secretion, as some have suggested. If that were true, we should see them in the periphery where retention is more pronounced. Serralach produced in dogs the connective tissue reaction seen in hypertrophy by repeated and frequent masturbation. But spheroids are seen at the time of life when the sexual activity usually becomes less frequent. However it must be admitted that attempts at frequent intercourse in men late in life, as an old man marrying a young active mate, usually induces prompt prostatic hypertrophy. Our attention was called to the similarity of the spheroids in the prostate and the lobular type of breast hyperplasia known as mazoplasia or adenosis. Mazer states the latter are due to hyperfunction of the anterior pituitary gland. Our fellow member Doctor Lower has shown in animals that injection of anterior pituitary extract will increase the size of the prostate and that testicular hormone will cause regression. Is it not possible they are similar in origin? We only offer this as a sug-
DEVELOPMENT O:F PROSTATE
481
gestion and realize that much work is necessary before definite conclusions may be drawn. CONCLUSIONS
The prostate is not a separate anatomical organ but the glandular portion of the bladder neck. There is no capsule dividing the bladder from the prostate. We see dilatation of peripheral acini which are not related to hypertrophy. Spheroids appear in the prostatic tissue in middle age and there is suggestive but not conclusive evidence that this is endocrine in origin. Medical Arts Bldg., Dallas, Texas.