In the eyelids one occasionally meets with cystic dilatations of the lacrymal ducts. These are known as dacryopic cysts or dacryops. Fistulas result when they are opened through the skin, and if meddled with at all they should be radically extirpated.[13]
[13] In the treatment of cysts, as of many abscesses (e. g., those of the gland of Bartholin), it will be of advantage to empty the cavity through a small trocar or needle and then to fill it with melted paraffin, as suggested by Pozzi. When it has thus been distended it can be dissected out with much more deliberation and more easily than would be otherwise possible.
Pseudocysts.
—In his elaborate work on tumors Sutton has made a distinct classification of pseudocysts, which lack some of the characteristics of genuine cysts, yet, nevertheless, are entitled to consideration in this place. Among these are included intestinal diverticula and vesical diverticula, in either of which instances hernial protrusions of the mucous membrane through the outer coating of the bowel or of the bladder occur, thus forming pouches. These are common in the bowel, rare in the bladder; especially in the former locality they are often multiple. This condition is often referred to as sacculation, and sacculation of the bladder may even be confounded with true urachus cyst. They are of little consequence so long as foreign materials, such as feces, urinary calculi, etc., do not lodge in them. But they occasionally cause serious trouble. Diverticula have been mistaken for appendices, while diverticula from the bladder have been encountered in hernia operations.
Pharyngeal diverticula give rise to rare but most interesting tumors. It is well known that the branchial clefts, which in early fetal life connect with the pharynx, are sometimes not completely closed, and that a portion of one may persist abnormally, giving rise to a condition known as the pouch of Rathke. There may also occur sacculation of the pharyngeal wall where it joins the esophagus, or hernial protrusions, especially in Rosenmüller’s fossa.
Cystic dilatation of Rathke’s pouch occurs near the upper part of the pharynx, and may attain the size of a marble. Hernial pouches are seldom mistaken for cysts, and are of importance mainly because of the fact that food or other foreign material gathers and lodges in them. Most of the other cystic abnormalities of the pharynx pertain to dermoids, and will be considered shortly. In a general way, these pharyngeal tumors have been grouped as pharyngoceles.
Similarly in the esophagus and trachea hernial protrusions occur, and lesions closely resembling retention cysts may be seen.
Synovial cysts (i. e., those containing synovial fluid) may arise (1) by protrusion of synovial sheaths, (2) by distention of bursæ in the vicinity of joints, or (3) by hernial protrusions of joint membranes. They are often met with in connection with the larger joints, more particularly about the knee. In this way tumors as large as goose-eggs may be formed, while their location may be so shifted that they present themselves in perplexing ways. To that form produced by hernial protrusion of the lining of a tendon sheath has been given the name ganglion.
The simple ganglion is frequently seen on the back of the wrist, and, while it is always connected with the tendon sheath, it undoubtedly often connects with the synovial membrane of the carpal joints. The compound ganglion, so called, is a much more serious and extensive affair, being one which has prolongations in two or more directions, and containing peculiar bodies, known as melon-seed bodies, which appear to be fibrinous concretions worn round and smooth by attrition. These are present sometimes in enormous numbers. (See [Tuberculosis of Synovial Structures], [Chapter IX].)
Bursæ are normal in many well-known situations in the body, but may undergo cystic dilatation and become annoying tumors. In many other places, under the influence of friction or mechanical irritation, there develop bursæ which are known as adventitious. These are sometimes subtendinous, and may communicate alike with joint sheaths and tendon sheaths. These are true cysts of new formation not developed from a pre-existing cavity.