HYDROCELE Origin and Pathological Anatomy. — As cysts may form where portions of embryonal ducts persist, so they may also develop owing to incomplete obliteration of the processus vaginalis along the entire route which the descending testicle traverses. There are several kinds accord ing to their persistence and locality, although there is no material differ ence between them.
In many cases the entire processus vaginalis remains and its periph eral part becomes distended through secretion of a serous fluid. Com munication with the peritoneal cavity is often very narrow and may become entirely occluded in isolated cases. If the pellicle remains open, there may be the picture of a changing hydrocele which becomes filled with serous fluid during the day when children run about, while during the night it may become evacuated; it may entirely disappear for a time and then reappear, lasting for a longer time. (Communicating hydro celc; see Inguinal hernia.) l'he processus vaginalis may also assume an hour-glass shape, so that one of the ampullte lies within the inguival ring and the other with out, perhaps in the scrotum. As they communicate with each other, they may alternately be filled or emptied. (Bilocular hydrocele.) That part of the processus vaginalis which normally persists as the tunica vaginalis testis, develops most frequently into a cyst. (Hydro cele testis.) Cysts may also develop in the shape of a rosary along the entire length of the seminal eord, a reminder of the embryological fact that the proccssus vaginalis does not undergo uniform and simultaneous involu tion. If a large portion of the cord persists as a cyst, there will be found a finger-shaped tumor accompanying the seminal cord and this is called hydrocele of the cord. (Hydrocele funiculi.) (Fig. 3S.) It is in the nature of these processes of development that with a widely open abdominal aperture of the processus vaginalis hernia may be associated with any form of hydrocele, a combination which is very frequently observed in hernia operations.
The etiology of this excessive accumulation of fluid in the remaining parts of the processus vaginalis is not yet completely clear. The theory that the source of the fluid is the peritoneum can only apply to cases where there is communication with the peritoneal cavity. For the other cases it is necessary to assume a hyperseeretion of the serous mem brane, such as also occurs in other similar organs, as for instance in the membranous sheath of the scrotum when traumatic and inflammatory processes cause a collection of fluid. (Difficult micturition, phimosis.) The inner membrane of the hydrocele has the histological character of the peritoneal covering (Foederl). If the hydrocele has existed for a long time, especially with intercurrent traumatic and inflammatory changes, traces of these arc present in the shape of cieatrieial thickening. The testicle is usually situated slightly above at the posterior wall, while in large hydroceles thf.s, typical position is obliterated.
Symptoms.—The first symptom is an increasing swelling in one-half of the scrotum. The other manifestations will, of course, depend upon the kind of hydroeele, as described above. The swelling is usually smooth and tense. When the tension is considerable, it is usually difficult to detect any fluctua tion. There are often annular constric tions at the places which correspond to the obliterations of the proeessus vaginalis. The tumor is transparent, displaying a reddish-yellow tint, which can be observed when looking through the tube of a monaural stethoscope.
Hydrocele cysts may occur also in the female along the round ligament, corresponding to the eanalis Nuckii.
Diagnosis.—The presence of an irreducible hernia forms the only diagnostic difficulty.
If the tumor is reducible, it can only he a hernia, except where there is a biloeular or communicating hydrocele, but in these cases the contents, consisting of intestinal coils or free fluid, can be easily made out owing to the slight tension.