Hertz' describes nerve-terminations in the smooth muscle-fibres of a uterine myoma. Delicate fibres, such as Frankerthiluser and Arnold have described, could be traced as far as the nuclei of the muscle-fibres. But since the examination of Hertz was made on a piece of tumor spontane ously discharged, there is no proof that the fibrils in question were really nerves.
Lorey' records a case of uterine polypus, consisting of smooth muscle, in which he plainly saw medullated nerve-fibres. In one microscopical specimen, a nerve-fibre was seen to end in a " terminal body." The soft fibromyomas are usually found near the fundus uteri. As a rule they occur singly, the multiple tumors belonging to the harder, more fibrous type. This latter variety is seen far more frequently than the former. It has been already stated that, the soft and succulent neo- • plasma are intimately connected with the substance of the uterus. Indeed this union is often so complete that it becomes difficult to isolate the tumor. But the hard fibroids are commonly distinct and separate from the surrounding structures, being enclosed in a sort of capsule. From the latter they can be easily enucleated. The capsule itself appears as a smooth cavity in the interior of the uterine substance. It originates from a pushing apart of fibres by the growth of the tumor, and never shows a true investing membrane. Even when the tumor has attained a very large size, uterine fibres completely surround it. But cases often occur in which at some point the uterine tissue has become so attenuated as to be barely discernible, forming only a narrow rim over the projecting mass of the tumor. Loose connective tissue is found between the sub stance of the growth and its capsule. And it is this circumstance which so greatly facilitates enucleation. In this layer of tissue and in the ad joining uterine substance, blood-vessels, principally of the venous kind, and often attaining a large size, abound. The arteries are generally smaller and are more scantily supplied. In some instances the uterine tissue imme diately surrounding such neoplasms shows a distinctly cavernous struc ture. From branches of these vessels the nourishment of the tumor is , effected.
As a general thing fibromyomata are of slow growth. Moreover it continues only during the period of functional activity of the sexual organs. It takes place in most cases in the direction of the least resistance to de velopment. This leads to important variations in the seat of the tumors, variations which materially affect the well-being of the patients. The
practical issues involved in this peculiarity will presently receive attention.
Fibroids may exist singly, or, what is more common, they occur in groups. Their size varies from growths not larger than a pea to tumors weighing sixty pounds or more, which fill almost the entire abdominal cavity. They are rarely met with in the cervix, their point of predilection being the posterior wall of the uterus. Next in point of frequency is the anterior wall, and then the fundus.' Thomas Lee observed only four cervical tumors among seventy-four myomas, and Courty mentions twenty-one out of a whole number amounting to 131.
Of greatest significance, as regards the symptoms and course, is the point at which the fibromyoma is developed. When the morbid process begins in the superficial, sub-peritoneal layers of the uterine tissue, the tumor, following the direction of least resistance, grows out into the ab dominal cavity beneath the peritoneum, constituting a so-called sub-serous fibromyoma.
If, on the other hand, the tumor arises within the uterine substance, in vading gradually the neighboring muscular layers, we have what is called an interstitial (intra-muscular or intra-parietal) myoma. Finally, tumors which begin in• the muscular layers immediately beneath the mucous membrane,•the direction of growth being chiefly into the uterine cavity, are designated sub-mucous. Strictly speaking, those tumors only should be called sub-serous which hang free in the abdominal cavity, attached by a loose pedicle, and covered only by the peritoneum; in those cases the only connection with the muscular tissue of the uterus is through the pedicle. In like manner, we should call those growths only sub-mucous which hang by a pedicle in the cavity of the womb, and which have no muscular coat. But neoplasms of this kind are also frequently designated fibrous polypi. These two forms differ from each other and from the interstitial variety, in symptoms, prognosis, and treatment. A strict ana tomical division, however, cannot always be maintained, at least.not during life. As soon as an interstitial fibroma has grown beyond the thickness of the uterine wall, unless its growth be exactly even on all sides, it will project more into the abdominal or uterine cavity, and thus become prac tically, as regards the symptoms, a sub-serous or a sub-mucous polypus. Anatomically, however, such a growth would still be classed among the interstitial tumors. Much more complicated, of course, are the symp toms in case of multiple tumors in different situations.