Seminal Colliculus

SEMINAL COLLICULUS (colliculus seminalis) (syn.: caput gallinaginis, veru montanum), is located in the prostatic part of the urethra on the lower (posterior) wall, at the border of the anterior and middle third of it [see Urethra (Vol. XIX, p. 176), Fig. 2]. Its length is approximately 8–10 mm, width 1.5–2 mm, and it has the same thickness. Posterior to it, two or three converging folds of the mucous membrane extend toward the internal sphincter of the bladder. Anteriorly, the seminal colliculus, gradually lowering, extends almost to the membranous part of the canal, where it splits into two folds in the form of ridges (frenulum). On both sides of the midline, on its lateral slopes, the ejaculatory ducts (ductus ejaculatorii) open, surrounded by a spermatic sphincter consisting of smooth muscle. At the apex, between the orifices of the ejaculatory ducts, there is an opening leading into the cavity of the prostatic utricle (utriculus masculinus, syn.: vagina masculina, sinus prostaticus, sinus pocularis). The latter represents a diverticular expansion located within the thickness of the seminal colliculus. Its cavity is lined with a mucous membrane with a large number of folds. In the thickness of the mucous membrane, tubular glands are often embedded. The epithelium covering it is multilayered cylindrical. The seminal colliculus has a hemispherical, less often ellipsoidal shape. Its surface is even and smooth, although depressions and irregularities are sometimes encountered. It is surrounded, as if wrapped, by a connective tissue sheath with an admixture of muscle bundles. Its reticular stroma consists of muscle and partly connective tissue, which in places either intertwine with each other or lie side by side, sharply demarcated from one another. The inner surface of the trabeculae is covered with multilayered cuboidal epithelium (Zaigraev). According to Henle and Rauber, the framework of the seminal colliculus is surrounded by cavernous tissue and permeated with venous cavities. Its vascular system is closely connected with the vascular system of the prostate gland. Nerves originate from the spermatic plexus, the middle hemorrhoidal, the lower vesical, and other nerves innervating the posterior urethra. The seminal colliculus, according to Klein, also has a large number of autonomic nerve fibers in the form of Pacinian corpuscles and Krause end-bulbs. The physiology of the seminal colliculus is not yet clear. Henle believes that its purpose is to prevent the ejaculate from flowing into the bladder during sexual intercourse and to hinder urination. Other authors, such as Finger and Vasiliev, believe that the seminal colliculus takes part in erection and ejaculation. Some authors attribute endocrine properties to the seminal colliculus, but there is not yet sufficient data for this. The methodology for examining the seminal colliculus consists of palpation of its area through the rectum; in its normal state, pressure on the area of the seminal colliculus is painless, but in case of inflammation, the patient feels pain and sometimes even an urge to urinate. Examination with a bulbous bougie, in addition to sharp pain during inflammation, gives a sensation of slipping, and in case of its hypertrophy, an obstruction during passage. Finally, by means of dry urethroscopy, one can determine its condition: a normal seminal colliculus usually occupies 2/3 of the lumen of a Charrière No. 23 tube. The mucous membrane covering it is reddish in color, somewhat more hyperemic than the mucous membrane of the upper wall of the urethra.

The cause of diseases of the seminal colliculus is most often various types of infectious inflammatory processes, especially of gonorrheal origin, and abnormal sexual activity in men (onanism, coitus interruptus), which cause congestive phenomena in the posterior part of the canal and in the seminal colliculus. Among other etiological factors, one should note mechanical or chemical trauma resulting from unskilled use of instruments, cauterization with strong solutions, or a diseased state of neighboring organs. In inflammation of the seminal colliculus (colliculitis), one finds its enlargement, hyperemia, edema, and small-cell infiltration with simultaneous desquamation of the epithelial cover and replacement of the cylindrical epithelium with squamous epithelium. The seminal colliculus is thereby enlarged, loosened, and bleeds and is painful upon touch. Massage of it through the rectum causes an admixture of blood in the urine, and in the most acute stages, this is observed even without massage. Vasiliev, on the basis of endoscopic examinations, divides the disease of the seminal colliculus into 4 groups: 1) chronic soft infiltrates, 2) hard infiltrates, 3) disease of the seminal colliculus with the presence of growths, 4) disease of the seminal colliculus with the presence of atrophic phenomena. The symptomatology of these forms manifests itself primarily from the sexual sphere: painful pollutions, premature ejaculation. Subsequently, weakness of erections, weak ejaculation, and weakening of orgasm may occur. Quite often, some increased frequency of urges to urinate is observed, as well as sensitivity and even burning during the passage of urine, which intensifies after defecation or after sexual intercourse. The observed changes in the nervous system are expressed in hyperesthesia or paresthesia of the mucous membrane. Patients complain of a feeling of pressure in the rectal area or itching radiating along the urethra or into the testicles. Due to hyperesthesia, reflex contraction of the external sphincter may be observed, as a result of which the stream of urine may be thinner than usual. Increased sensitivity manifests itself in the form of attacks of neuralgic pain, which can be not only in the area of the prostate and posterior urethra but also radiate to the glans penis, the testicles, and even the lower back. Any trauma to the perineum leads to an intensification of painful sensations. Among other diseases of the seminal colliculus, growths of a granulation or polypous nature are most common. Polyps appear as single or multiple, can be thin, thick, sitting massively on a broad base, and can cause an admixture of blood to the urine and semen. Hypertrophy of the seminal colliculus is a fairly frequently encountered form of the disease, which in its symptomatology from the sexual sphere differs little from other diseases of the seminal colliculus; disorders of urination are often observed with it. The seminal colliculus in this case is sharply enlarged, smooth, or resembles a mulberry in its shagreen appearance. In sclerotic processes leading to connective tissue degeneration, and sometimes atrophy, narrowing or even complete compression of the lumens of the ejaculatory ducts may be observed, causing azoospermia.

Treatment of inflammatory forms comes down to instillations of silver nitrate solutions (from 0.5% to 1%) into the posterior urethra, to smearing the seminal colliculus with a 5–10% silver nitrate solution, whereby the concentration of the solutions used for smearing must be in inverse proportion to the acuteness of the process. In sharply expressed changes of a connective tissue nature and in atrophic processes, heating with diathermy can be applied with success. In the presence of growths of a granulation nature or polyps, electrocoagulation or galvanocauterization are the best methods of treatment and can be performed both through a Valentin dry urethroscope and through a Vossidlo irrigation urethroscope.