Hypertrophy of the prostate is so insidious in its mode of invasion, that theonly indications of its occurrence are evinced by the mechani cal impediment to the free discharge of the urine, in consequence of the increa.sed size of the gland. No pain, no uneasiness is felt be fore the prostate has obtained a considerable volume, after which, symptoms of a most dis tressing character set in, and continue, with more or less severity, to the termination of the patient's existence. It would be out of place here to enter into the signs which cha racterise the progress of this disease. I must confine my observations to the state of the gland itself, to the effect produced upon the adjacent structures by its enlargement, and to its cause.
In senile hypertrophy, the gland becomes enlarged in all its dimensions ; it expands laterally, extends downwards towards the rec tum, so as to be readily felt, forming a consi derable tumour in this situation, and upwards behind the symphysis pubis, so that in a thin person, with the hand firmly pressed upon the hypogastric region, the surgeon can, in some cases, feel it distinctly. Its outer sur face is smooth and round, or occasionally irregular and nodulated : the two lateral lobes expanding universally, are pressed together, so as to become flattened at their opposed surfaces ; if one increases particularly at one part, as is often the case, there is a corre sponding indentation in the other, and thus the direct course of the urethra is altered, and the canal is twisted in various directions. The disease is not usually confined to its lateral lobes ; for the third lobe frequently participates in the enlargement. This may happen to a great extent, in some measure, independently of the increase in size of the lateral lobes ; but usually, where the middle lobe is affected, the lateral lobes are enlarged, although the converse of this condition is not so invariable. The middle lobe sotnetimes forms a simple pyramidal elevation at the urethral orifice ; sometimes a large pendulous or valvular tumour, occasionally rising up wards from the posterior part of the prostate in the mesial line direct, frequently inclining to one side. It has been known to attain the size of a small orange ; and where it has in creased to such an extent, it must of neces sity happen that the base of the tumour is the smallest part of it. Whatever form of en largement the middle lobe assumes, the tumour always projects towards the bladder : it is frequently knotty or lobulated on the surface. In its increase, the third lobe draws up the prostatie portion of the urethra, and elongates -.he veru montanum. Very great interest has attached to this condition of the middle lobe, in a surgical point of view, since Sir Everard Home particularly directed the attention of surgeons to Mr. Hunter's observations upon it, who states " that it sometimes increases so much, as to form a tumour projecting into the cavity of the bladder some inches." The disease of this part of the gland had not escaped the observation of Morgagni, although he did not attach much importance to it : it was also known to Valsalva.
Hypertrophy of the prostate is frequently attended with general induration, so that when cut into, it almost resembles cartilage. This has obviously given rise to the term seirrhous prostate, as applied by the older surgeons to the disease in question. In other instances, it feels softer than natural. The capsule be comes gradually attenuated by distension, and the direction of the tumour is alvvays towards the part where there is least resistance.
It has been very commonly asserted that the left lobe is more frequently hypertrophied than the right. The observation originated with Sir Everard Home. I cannot deny the truth of the assertion; but it is divested of any practical importance, as it is well known that the right lobe is in very many cases the larger of the two. However, the fact that the two are very frequently unequally enlarged, ought to be impressed upon the mind of the surgeon, as he inay expect that the course of the urethra will deviate to either side, and (in the introduction of the catheter) in cases of re tention, from enlarged prostate, he must direct his instrument accordingly.
The enormous increase of size which the prostate attains, produces serious incon venience to the parts adjacent. Thus, inde pendent of the effect on the nerves of the pel vis, as indicated by pains in the loins, sacrum, groins, and down the thighs, its influence is most sensibly perceived in the altered state of the urethra, in the bladder, and the rectum. By the enlargement of the prostate, the urethra is increased in length —a fact well known to practical surgeons. This actual elongation takes place only in the prostatic portion of the canal ; the diameter of the urethra, so far from being diminished, is really increased ; but the part surrounded by the gland is al tered in shape ; for, whereas in the natural state the prostatic sinus is longer in a trans verse than in a vertical direction, it is now quite the reverse : its sides are also approxi- • mated by the coaptation of the lateral lobes ; and if any unequal projection of either lobe exists, it takes a tortuous course to reach the bladder, or reaches it by two channels, one on each side of the middle lobe ; besides which, the urethral orifice into the bladder is more or less blocked up by the projection of the middle lobe, or is raised higher than na tural, the prostatic part of the canal forming a sickle-like curve, the convexity of which is downwards. The prostatic sinus is occa sionally dilated to such an extent, as to be capable of holding two ounces or more of urine. The veru montanum is placed at a greater distance than natural from the bladder. The bladder becomes either preternaturally dilated, or contracted to a very small size; these two opposite conditions probably de pending on the greater or less irritability of the viscus ; sometimes it is sacculated ; its muscular coat is thickened, and its mucous lining becomes the seat of acute or chronic inflammation, with all its accompanying pa thological changes. So also the ureter and even the kidneys themselves are frequently diseased in the advanced stages of this affection. When the third lobe is much enlarged, it throws the neck of the bladder forwards, and increases the depth of the inferior fun dus to such a degree, as to cause the lodgment of calculi in its cavity. In one respect, this circumstance is attended with some advantage, inasmuch as it lulls the symptoms of stone, by preventing the calculus from coming in contact with the sensitive neck of the bladder. But an obvious inconvenience arises in other cases from the difficulty of seizing calculi under such cir cumstances, in the operation of lithotrity ; and after a calculus is broken up, it prevents the escape of the fragments, and thus favours the recurrence of the disease.