Congenital cysts of the corpus uteri

Abstract

Congenital cysts of Müllerian-duct origin present a varied picture. The various anatomical types which have been reported are the pedunculated submucous, submucous, intramural, subserous, pedunculated subserous, and parasitic. Most common are the subserous or pedunculated subserous types. They are usually found in or near the midline. In about half of the cases they are found on the posterior wall of the uterus, but they may also be found on the fundus, anterior wall, or cervix. The cysts are most often found singly, but several cases of multiple cysts have been described. The lining epithelium may resemble endometrium, endosalpinx, or endocervical epithelium, or may be of a primitive Müllerian-duct type. The usually found columnar epithelium may show flattening due to the pressure effect from the expanding contents of the cyst. In places the epithelium may be missing. The epithelium is often found lying on a hyalinized layer of submucosa, and may be thrown up into ridges and papillary projections. The wall of the cyst is usually composed of smooth muscle with varying amounts of fibrous-tissue elements. No communication with the uterine cavity was demonstrable in any of the reported cases.The average age of the patients in whom these cysts have been found is 36, and the age range is from 25 to 52 years of age. They occur more frequently in women who have borne several children. The symptoms are nonspecific, being those of a lower abdominal mass. The most frequent preoperative diagnosis is that of an ovarian cyst or myomas of the uterus. The treatment depends upon the size and location, and consists of either excision of the cyst or hysterectomy.These cysts are generally considered to be benign in nature. Dworzak12 described a case which he thought to be one of Müllerian-duct origin with malignant degeneration of the epithelium. However, the description of the case gives one considerable reason to suspect that he might be dealing with an interligamentary papillary cystadenoma of the ovary. A case of this type was later described by Fukushima13, in which metastasis from a previously removed papillary cystadenoma of the ovary gave rise to several uterine cysts which superficially resembled the type of cyst in question.The generally adhered to theory of origin is the one first proposed by Kossmann and elaborated and established experimentally by Frankl and Meyer. This theory states briefly that the cysts are derived from the invagination of the Müllerian ducts as they grow together and fuse in the midline to form the fundus and body of the uterus.