Epithelioma Adamantinum

from the Clinical History.--The patient, female, aged thirty years, was admitted to St. Joseph's Hospital. Two years and three months ago she first noticed a small, hard tumor near the first bicuspid tooth on the left side of the lower jaw bone. It grew slowly. In childhood there was nothing unusual about her teeth, which were perfectly regular and even up to the time of her present illness. Examination shows that the tumor extends from angle of jaw nearly to the median line. The dentist of the patient furnished the following history. Two years and three months ago the patient consulted him for what she considered to be an abscess in connection with a tooth. The enlargement 378 Epithelioma Adamantinum was apparent both inside and outside the mouth and was quite painful. As nearly as he remembers the teeth were all intact, the crowns being normal and no fillings having been introduced. The inferior maxillary bone was enlarged in the neighborhood of *he first and second molar teeth, both of which were loose. On extracting the second molar no fluid appeared. On extracting the first molar there was a considerable discharge of ~hin, brown fluid without odor (evidently the contents of a cyst). The roots of the extracted teeth were almost absent. The patient was referred for treatment to St. Joseph's Hospital, where an operation was performed by Dr. Nathan Jacobson. Six months after operation there is no evidence of recurrence. Abstract from the Pathological Record.--The specimen consists of part of the left lower jaw bo~e, extending from the angle nearly to the median line. The enlargement begins about 3 cm. anterior to the angle of the jaw and involves the bone for a distance o~ 7 cm. The tumor measures ~ x 3 cm. I t is covered with a thin shell of bone. There are at my disposal for description a few small blocks of tissue from the tumor fixed in Zenker's fluid and decalcified in five per cent nitric acid. In this tissue the cystic quality of the tumor is evident. The largest cyst seen is 7 ram. in diameter and is empty. Sections are cut in parafiCin 6/* thick, and stained with eosin and methylene blue. :MicroscoPicAL EXA~I~AT~ON.--:Many of the sections show the mucous membrane of the mouth and a thin shell of bone and fibrous tissue surrounding the tumor. The layer of bone is interrupted in many places. The areas of bone are partially surrounded by osteoblasts and an occasional osteoclast is seen. The tumor itself consists of a connective-tissue stroma, in which there are alveoli formed by epithelial cells. The appearance under low power is well reprosented in Bors.t's (4) plates. The epithelial elements represent the enamel organ and are largely in the stage corresponding to the greatest development of the stratum mueosum (Fig. 1). One or two areas, somewhat removed from the periphery~ represent the stage immediately preceding the development of the stratum intermedium and the stratum muoosum (Fig. 2, c). :No definite karyokinetic figures are seen here~ but some nuclei stain more deeply than others and have a t t . S. Steensland 379 slightly ragged surface. This is represented at d, Fig. 2, where, apparently, the stratum intermedium is beginning to develop. Intercellular bridges, perhaps corresponding to those of the epithelium of the mucous membrane of the mouth, are seen. The appearance here suggests carcinoma. In many places the stratum mucosum is largely replaced by cysts containing a finely granular material staining with eosin. Anastomosis of the alveoli suggests that the epithelial constituents form a solid framework similar to that which has beeu shown to exist in carcinoma by means of reconstructed serial sections. In the large alveoli is seen an external layer of cells, which in some places are cylindrical, in other places cubical (Fig. 1, a). The layer is occasionally invaginated and therefore appears in the section to be situated inside of the alveolus. The cylindrical cells perhaps correspond to the inner epithelial layer of the enamel organ, the cubical cells to the outer epithelial layer. Often, but not regula)ly, within the external layer are one or more layers of flattened cells, which tend little by little to assume the stellate form and correspond to the stratum intermedium (Fig. 1, b). Occupying most of the interior of the solid alveoli is the most characteristic feature of the tumor, the stratum mucosum, or enamel pulp, consisting of anastomosing stellate cells (Fig. 1, c). When seen under a lower power it might be mistaken for mucoid tissue and, especially when present in large areas, might lead to a diagnosis of myxoma. There are invaginations of the external layer of cells which with the adjacent stroma simulate the " Anlagen" of teeth in their early stages (Fig. 1, a). This gives to the alveoli the appearance of gland tubules in a stroma of mucoid tissue (Fig. 1), especially in places where the invaginated stroma has largely lost its fibrillar character and appears homogeneous (Fig. 1, d). Evidences of karyokinesis are seen in the external layer, and to a less extent in the stratum intermedium. Various stages in the development of cysts are well seen. They are due evidently to a hyaline and granular degeneration of the stellate cells and to an accumulation of fluid between these cells. The formation of the stratum mucosum is apparently associated with 380 Epithelioma Adamantinum an accumulation of fluid between the cells, the formation of long processes of the cellular protoplasm, and the gradual disappearance of the intercellular bridges (Fig. 1). No evidence of enamel, dentine, or cement is seen. CMbret (~) has described the formation both of enamel and of cemento-dental tissue in a similar tumor. The stroma (Fig. ~, a) consists of dense connective tissue in which only a few blood vessels (Fig. 2, bb) are apparent. The tumors under consideration probably originate from structures described by Ma]assez (1) as paradental epithelial d~bris (d~bris ~pith4liaux paradentaires). A rational theory of the histogenesis of this class of tumors dates apparently from the publication of his first article. He carefully describes and illustrates these cell masses as they occur in the adult and discusses their histogenesis. He attempts to explain how epithelial tumors may originate in the bodies of the jaw bones at a considerable distance from surface epithelium. In the intra-alveolar tissue surrounding the roots of norreal teeth he has found masses of cells, and from a study of the developing jaw he concludes that these masses represent the remains of the dental ridge and some of the epithelial structures originating from it, especially the neck and the outer epithelial layer of the enamel organ. A consideration of the histogenesis of adamantine epithelium suggests the possibility that adamantine tumors may arise from the gingival epithelium and from any of the derivatives of the dental ridge. The cellular masses described by Malassez are distributed in the alveolo-dental ligament from the apices of the roots to the epithelium covering the gums. The " dSbris " may be present in the marrow spaces of the jaw bones entirely outside the alveolo-dental ligament. This fact furnishes an anatomical basis for the origin of tumors of the jaw bones more or less independent of teeth. Efforts have been made to associate the etiology with irregularities in the development of the teeth, with inflammatory processes, trauma, etc. ; but these conditions are probably secondary rather than primary. The sex of the individuals affected is stated in eighteen recorded cases, eight occurring in men and ten in women. The age when H. S. Steensland 381 the turhor was first noticed could be estimated in sixteen cases. The youngest individual was eight years of age and the oldest, fifty-eight. The greatest number of patients, five, were in the fourth decade, In two other cases the specimens are described as consisting o£ the jaw bones of adults. I t has been thought that these tumors are prone to occur in young individuals, especially during the period of dental development. The description and figure from a case described by Massin (8) as congenital do not give evidence that he observed a tumor of this class. The location of the tumor is mentioned in twenty cases; seventeen times it was situated in the lower jaw, twice in the upper. Becker (5) has called attention to a possible influence of the difference in anatomical relations. In the maxilla perhaps such a tumor might grow into the sinus and not cause any apparent swelling or other prominent disturbances; possibly indefinite neuralgic and other symptoms might be caused in this way. The situation appears to be as frequent on one side as on the other. In the lower jaw the main mass of the tumor is most frequently at the angle of the jaw. From here it may extend upward to the articular surface and' into the coronoid process and ventrally as far as the median line. In one case the tumor is said to have implicated one entire inferior maxilla; twice the location was in the body ventral to the angle and four times its position was median. Of the two cases affecting the upper jaw, both were on the left side and in one of these the sinus had been invaded. In Case No. 13 (see Table) both sinuses were invaded and both sides of the lower jaw bone were implicated. A median position in the upper jaw is not mentioned. These tumors develop in the interior of the jaw bon~e which remains as a thin parchment-like covering. At the time of operation they have varied in size from that of a plum to that of the head of a foetus, but are most frequently about the size of a hen's egg. In two cases it is stated that the tumor was easily separable from the surrounding bone, which suggests that it was encapsulated. In four cases no macroscopical cysts were present, the tumors being solid