CHAPTER V.

HYPERTROPHY OF THE PROSTATE-ITS ANATOMICAL

CHARACTERS.

External Characters of Hypertrophied Prostate.-Parts chiefly affected.-Amount of Enlargement produced. - Changes in Urethra and Neck of the Bladder which result. -Internal or Structural Changes produced. -Varieties of Hypertrophy.

HYPERTROPHY OF THE PROSTATE. Among men who have passed the prime of life, or, to speak more definitely, those who have passed the fifty-fifth year, or thereabout, as far as the most carefully prosecuted researches tend to show, a peculiar affection of the prostate is commonly, but by no means generally, met with. The organ enlarges by a slow and gradual process, and almost always produces more or less obstruction to the discharge of urine from the bladder. This enlargement, as will be seen. when we consider the details of the subject, is not a product of inflammatory action, nor is it caused by any results of inflammation corresponding with those which constitute inflammatory enlargements in other organs; that is, the albuminous, fibrinous, or other exudations, such as occur in lymphatic glands, for example; but it is due to an increased formation of the normal tissues of the prostate, and may therefore be fairly classed as an hypertrophy.

MORBID ANATOMY.-It will be convenient to study the morbid anatomy of this affection under the following heads:

I. The external physical characters belonging to the Hypertrophied Prostate.

II. The parts of the Prostate chiefly affected by Hypertrophy.

G

III. The amount of Enlargement produced by Hypertrophy. IV. The anatomical changes in the Prostatic Urethra and neck of the Bladder induced by the Hypertrophied Prostate.

V. The internal or structural changes observed in the Hypertrophied Prostate.

I. EXTERNAL PHYSICAL CHARACTERS.-It has been already seen that it is scarcely possible to describe, in exact terms, the limits, in respect of either weight or size, of a healthy prostate, any addition to which must necessarily and consequently be regarded as indicating hypertrophy. By some observers a weight exceeding six drachms has been regarded as always abnormal. Absolute proof of this appears to be wanting, but I think that seven drachms may fairly be considered as indicative of hypertrophy when found in a subject of about 60 years of age. I have never seen such a prostate which did not present other indications either of external physical, or of internal structural, changes, corroborating the suspicion aroused by the fact of weight. On the other hand, I have seen a prostate weighing less than six drachms, which afforded unmistakable evidence of the existence of hypertrophy in the conformation, &c. The possibility of this can be easily understood when we recollect that in some individuals a prostate of less than four drachms is of normal size.

The first external character generally observable in a hypertrophied prostate is undue fulness, and an unnatural tendency to rotundity. Almost always the gland is thicker than natural, Neither the length nor the transverse measurement may be necessarily increased, while the measurement from before backwards (erect position) is almost invariably increased. Hence the fulness remarked. The surface-markings described in the section relating to healthy anatomy disappear; the external indications of bilobular formation diminish. If a section now be made through the anterior part (anterior commissure), so as to lay open the urethral canal longitudinally, the lateral lobes appear fuller than natural, and to protrude a little into the passage, so that their opposed sides press lightly upon each other.

EXTERNAL CHARACTERS.

83

In a more advanced stage, the enlargement is more considerable; either lateral lobe may predominate, or the portion behind the verumontanum, " median portion," may be largely developed. The form or outline of the gland may be very irregular and unsymmetrical from the presence of projecting portions, which may result from two conditions-first, either lobe may protrude greatly beyond the others, as just alluded to; or, independent tumours may be found embedded in it, or only partially so, springing from the surface, and forming very salient projections in any direction, most commonly, however, towards the cavity of the bladder. When these are present and largely developed, the original form of the prostate is often altogether obscured, and a mass of rounded prominences, sometimes numerous, and generally irregularly placed, surrounds the neck of the bladder. (See Plate VIII.) In any of these conditions the urethra, as it passes through the prostate, may be diverted a little right or left of the middle line by pressure, from the most enlarged part; the prostatic portion may be increased in length (necessarily with the increased length of the prostate itself), and the antero-posterior diameter of the canal is often much increased by reason of the enlargement of the lateral lobes. To all these changes the capsule accommodates itself, and increases commensurately with the increasing gland.

In external colour there is no difference ordinarily observed; unlike to malignant enlargement, in which heterologous formation and increased vascularity are accompanied by marked yellow, red, and violet tints in some variety of shade.

In consistence, there is usually some change; the hypertrophied prostate is most commonly more firm and dense to the touch than the healthy one experiences a sensation suggestive of structures firmly bound within a tight or stretched envelope, the truthfulness of which is apparent if a section is made, when the contained parts protrude, or the containing parts recede, so that the cut surfaces become more or less convex. In a few exceptional examples this does not occur, but it is undoubtedly the rule.

II. The parts of the prostate which are chiefly affected by hypertrophy.

There is no part of the prostate which may not be affected by hypertrophy. The lateral lobes, the median portion, or middle lobe, the anterior and posterior commissures are all capable of exhibiting this change, although in different degrees of extent, as regards both their several liability to be affected, and the extent which development may attain when the affection has taken place.

The data for forming a conclusion on this subject, and those are now numerous, show that no one portion of the organ exhibits any marked predominating tendency to enlarge above the remaining portions, either in point of early manifestation, rapidity of growth, or extent of development.

Writers, and surgeons generally, seem to attribute the first disposition to enlarge to the median portion ("middle lobe"), as well as to regard this as the source of the most considerable development in point of size. As regards the locality of commencing enlargement, I do not think the median portion exhibits. the change at an earlier period than the lateral lobes, but, as regards the rate of development, the former, perhaps, progresses more rapidly than the latter. At the same time, most of the preparations contained in four of the principal museums of London, including that of the Royal College of Surgeons (each one of which I have carefully examined, and possess written notes respecting), amounting to a total of 123 specimens, exhibit about an equal development in size of at least three portions of the organ; that is, of the lateral lobes and median portion, while in many the anterior commissure is correspondingly enlarged. I have classified the preparations referred to in distinct groups, marked by the direction or situation in which the enlargement is chiefly manifested, a method which will afford the means of obtaining a comprehensive view of the question under consideration. The first group consists of the four varieties of form which most commonly occur; the second group of three varieties of form which are decidedly rare.

AFFECTED BY HYPERTROPHY.

85

Uncommon

forms of the

affection.

Common forms of the affection.

I. General enlargement of prostate, that is, both lateral lobes and median portion pretty equally enlarged, is present in 74 preparations of the 123.

II. General enlargement of prostate, but the median portion enlarged in greater proportion; in 19 preparations.

III. General enlargement, but the right lobe predominating, and very decidedly larger than the left; in 8 pre parations.

IV. General enlargement, but the left lobe predominating, and decidedly larger than the right; in 11 preparations.

V. The lateral lobes only enlarged; in 5 preparations. VI. The anterior commissure only, or chiefly enlarged; in 3 preparations.

VII. The lateral lobes and anterior commissure enlarged, not the median portion; in 3 preparations.

The several series of preparations tabulated in Chapter II. furnish results very closely corresponding with the foregoing, including two series of 64 preparations by myself, and another, by a wholly independent observer, Dr. Messer, formerly of the Royal Naval Hospital, Greenwich. All these present results more valuable than those obtained from museums, because they consist of average and not of selected specimens. Among 100 prostates from subjects of 60 years old and upwards, Dr. Messer found 35 which were enlarged. He reports, that in 17, or about one-half of the number, "all these lobes were pretty equally enlarged;" that in 14 both lateral lobes were chiefly affected; that in one case the left lateral and middle lobes were mainly affected; that in one the right lateral lobe was mostly; that in one the left lateral lobe was alone; and that in one the middle lobe ("median portion") was chiefly affected: in all 35.*

See a valuable report on this and other questions connected with the Anatom and Diseases of the Prostate, by Dr. Messer. Trans. Med. Chir. Soc., vol. xliii., p. 153.