symposium on maxillofacial bone pathology

lnt. J. Oral Surg. 1975: 4:80-92 International Meetings

Symposium on maxillofacial bone pathology

The Symposium was held on 30-31 March 1974 in Brussels by the Belgian Group for the Study of Maxil lofacial Bone Pathology and was at tended by some 200 participants f rom all Common Market countries. Ex- perts were invited to give papers on two selected topics: 1. Odontogenic tumors and 2. Sarcomas of the jaw bones.

Emphas is was on histology for defining acceptable criteria for diagnosis, terminology and classification. There was fairly uni form agreement about nomenclature of odontogenic tumors, as most participants appear to accept and use the W H O classification. This was not the case, however, with jaw sarcomas, where there was con- siderable confusion over terminology. Nev- ertheless, many pathologists use a nomenclature which closely conforms to that ad- vocated by the WHO, in which malignant tumors are clearly separated and defined by the mesenchymatous elements present. I f aII or some of this malignant tissue pro- duces bone, the tumor is an osteosarcoma; if cart i lage but no bone is produced (except by enchondra l ossification) it is a chondrosarcoma, and if nei ther of these elements is present the tumor is a fibrosarcoma. On the other hand there are valid reasons for grouping these various histologic types of sarcomas of bone under the title "osteogenic sarcoma".

Several variations in terminology and concept caused problems for the Sympo- sium organizers in their at tempt to formu- late points for discussion.

The papers given also drew attention to the discrepancies in histologic diagnosis and prognosis. Fo r instance, the difficulty in clear ly separating well differentiated fibro-

sarcomata from fibromatoses and pseudo- sarcomatous fasciites or osteosarcoma from juxtacortical osteosarcoma could well be responsible for the variat ion in the content of different series. Improvement and stan- dardizat ion of diagnosis in this field is therefore mandatory.

Meanwhile, it appears from the papers given at this Symposium that: (1) pr imary sarcomas of the jaws are exceedingly rare, (2) they have a better prognosis than similar neoplasms in other parts of the skeleton, and (3) although rare, chondrosarcoma of the jaws has a poorer prognosis than in other sites.

Surgery is still considered the treatment of choice in most cases, but interesting results have been achieved with chemotherapy and radiotherapy.

I t would appear from the many aspects discussed in this Symposium that a special study of these lesions is warranted and that international co-operation would be essen- tim for a significant sample to be collected.

W. H. BINNIE EL. DE LATHOUWER England Belgium

EL. BROCHERIOU A . K . PANDERS France The Netherlands

F. P RA.ETORIUS Denmark

Sarcomas of the jaws

J. J, PINDBORG (Copenhagen): Terminology and classification of osteosarcomas In 1972, the WHO's bone tumor group published its monograph on "Histological Typing of Bone Tumours" after 9 years of work. In that book, osteosarcoma is de-

SYMPOSIUM ON MAXILLOFACIAL BONE PATHOLOGY 81

fined as "a malignant turnout, character- ized by the direct formation of bone or osteoid tissue by the tumour cells". The speaker also discussed the terminology and classificatiort used in the AFIP fascicle on bone tumors. I t is a generally accepted practice to divide the osteosarcomas into fibroblastic, cbondroblastic, and osteoblastic types. According to some authors the fibroblastic type has a better 5-year survival rate than the other types.

C. I. SMITH & G. T. GRA~G (Sheffield): The frequency o)r sarcomas of the law bones The frequency of occurrence of sarcomas in jaw bones has been assessed by different methods of approach using three sources of material. Diagnostic histopathologic specimens in the files of the Departmertt of Oral Pathology, University of Sheffield, were reviewed for the period 1949-1973 inclusive. A total of 7,121 specimens contained 18 that had been classified as jaw sarcomas, compared with 218 pr imary oral squamous cell carcinomas and 7 metastases in jaw bones; there were 9 osteosareomas (g in mandible, 1 in maxilla) and 2 chondrosarcomas (both in maxilla). Data from the Sheffield Regional Hospital Board Cancer Registry reveal approximately one newly registered jaw sarcoma each year in a population of about 4a~ millior~; jaw sarcomas form approximately 3 % of sarcomas af- fecting all bones. ReIevant informatiotl from published l i terature on jaw sarcomas had also been analyzed. Two major problem areas have been identified. One of these relates to diagnostic accuracy, con- sistency of terminology and criteria for reg- istration; the other concerns the breadth of interpretation of the category "sarcomas of jaw bones". These opportunities for error and misinterpretation, together with the very low incidence of jaw sarcomas, encour-

age the suggestion that current statistical data should be interpreted with caution; Furthermore, standard criteria must be es- tablished before figures concerning the frequency of sarcomas of jaw bones can be considered reliable.

H. N. HADDERS (Groningen): The histologic typing and grading o~ chondro- and [ibrosarcomas localized in the laws and in other parts of the slceleton Of 356 ehondrosarcomas collected in the Registry of the Netherlands Committee on I/lone Turnouts, the exact localization of 300 was known. Seven were in the mandible and four were in the maxilla. All chondrosarcomas were classified histologically into one of three grades (I is least, II][ is most malignant). There is a correla- tion between the histologic grading and the time of survival both for the minors of the jaws and elsewhere in the skeleton: Grade I has a far better survival t ime than Grade III. The exact localization of ;106 i ibrosarcomas was known. Of these pr imary tumors, 13 were in the mandible and fore" were in the maxilla, a remarkable difference in frequency compared with the chondrosarcomas. The fibrosarcomas were also histologically, classified into three grades. After comparing these three groups with the time of survival, again a correlat ion was found. We have the impression that the prognosis of fibrosarcomas and ehondrosarcomas Grades II and I I I is a bit more se- rious when the jaws are affected, but we have had too :few cases to be able to draw a definite conclusion.

R. O. VAN OER HEUL (Rotterdam): Osteo- sarcomas of the jaws Of 20 patients, the tumor was localized in the mandible in 9 and it1 the maxilla in 11.

82 SYMPOSIUM ON MAXILLOFACIAL BONE PATHOLOGY

Eighteen patients were observed for a pe- r iod of up to 5 years and seven were aRve af ter 5 years. Of these seven, one died of myoca rd ia l infarction and another devel- oped lung metastases after 6 years. The lung was surgically removed, resulting in continuing good heal th 3 years later. The dea th within 5 years of 1i patients was due in seven cases to local extension and in four eases to metastases. The osteosarcomas of the jaws were compared with those elsewhere in the skeleton which were collected in the Registry of the Netherlands Commit- tee on Bone Tumors from 1953 up to the first of January, 1967. Like most cases of j aw sarcomas, osteosarcomas located in long tubular bones (a total of 266) can be t reated by radical surgery, so these cases were selected for comparison. W e found that only two histologic features correlate with the prognosis: the mitotic frequency or index and the presence of a baste pat tern of interlacing bundles of cells and fibers (fi- brosarcomatous type of osteosarcoma). Abou t 40 % of our patients with a jaw osteosarcoma are alive 5 years after treatment and only 2 1 % of the others. Of those 40 %, near ly all had an osteosarcoma with a mitotic index of 8 or less, a feature favoring a better prognosis. There were five patients with a j aw sarcoma of the fibrosar- comatous type, i.e. 25 % (in the whole series it was 16 %). Taking into account the small number of jaw tumors it is doubtful that this difference has any meaning. However, despite the small sample, it appears that osteosarcomas of the jaws are more likely to show the histologic features favoring a good prognosis than are osteosareomas of long bones.

eL. BROCHERIOU (Paris) & J. PAYEN (Poi- tiers): Cartilaginous tumor,r of the jaws Over a 20-year per iod at the Institut de

Stomatologie de la Salpgtri6re, Paris, there have been four benign cartilaginous tumors and seven chondrosarcomas in a total of 585 jaw tumors. The chondromas and oste- ochondromas were found along the anterior midline of the maxilla, and in the coronoid process, condyle and mandibular symphysis. The chondrosarcomas were found in young males and most commonly in the maxilla. Of six cases followed, five d ied within 4 years and one survived 7 years. Chondro- sarcomas have a poorer prognosis when in the jaws than osteo- or f ibrosarcomas.

I . M. FACCINI (London): Yuxtacortical (par- osteaO osteosarcoma of the mandible The juxtacortical (parosteal) os teosarcoma is now a well-recognized entity in long tubular bones but as yet appears to have been described only rarely in the jaws. The features of two cases of this type in a 50-year- old woman and 48-year-old man are described. The characteristic, well differentiated nature of the tumors bo th radiologi- eally and histologically lead to delays in diagnosis and treatment that emphasize the need to be aware of the occurrence of such sarcomas within the jaws.

N. DouRov & CL. DE LATHOUWER (Brus- sels): Problems of diagnosis in a case of mandibular fibrous tumor. Electronmicro- scopic study An intraoral tumor is described in an 8- year-old boy who was otherwise in good health, l i e had an excellent denti t ion apar t from the primary mandibular left first molar, which had abscesses and was extracted. The tumor (3 • 4 cm) grew rapid ly in 15 days and was firm and granulomatous in appearance. There was labial hypoesthesia and the orthopantomogram showed a well defined radiolucency. The clinical appear-


an te was that of a giant cell reparative granuloma. Histologic sections were examined in various Belgian and other centers without any agreement being reached. The eoncensus was a well differentiated fibrosarcoma or fibroblastic tumor, and radical surgery did not appear necessary. Eight months Iater, clinical and radiologic exam- ination showed complete healing of the op- erated site. Electron microscopic examina- tion confirmed the cells to be fibroblasts in close relat ion with collagen fibers. No ul- t rastructural atypia were observed. This case illustrates the diagnostic problems of f ibrous lesions and the possible influence on the 5-year survival rate of small series of sarcomas when such lesions are in- eluded.

G. F. LEROUX (Liege), L. JEANMART (Brus- sels), F. ]-IOTTON (Brussels), F. REYOAERTS (Leuven) & A. BAERT (Leuven): Contribu- tion oy radiology in the diagnosis of malignant tumors of the ]aws Since i958 there have been six malignant neoplasms of the maxilla and ten of the mandible in Belgium. Comparison with the number of similar tumors seen in long bones shows that this is a very rare condi- t ion in the jaws. Radiologic diagnosis is difficult because of the variatiorl in radio- graphic appearance and because of the small number available for study. The authors recommend that a prospective study, such as has been suggested by Lodwick for mal ignant tumors of the skeleton, is necessary for accurate diagnosis.

which appear statistically to affect the origin and behavior of bone sarcomas. The influence of ionizing radiation is generally accepted. I t seems more evident in the jaws than in other locations. The carcinogenic effect of radiotherapy seems more pro- nounced when the irradiated disease is a fibrous dysplasia or a giant cell tumor. These two lesions are also susceptible bu t they seldom degenerate spontaneously. Paget's disease constitutes a presarcomatous factor, which varies in different countries and depends on the age of the patient and the severity of the disease. Nevertheless, Paget's disease has been found less frequently in the jaws than the higher age group of patients presenting sarcomatous lesions of the jaws would have suggested. Other lesions, such as enchondromas and osteocartilaginous exostoses, do not seem to be presarcomatous in the jaws and are a very rare occurrence in this site.

R. DOUNIAU ~; (}. DELIRE (Louvain): Trau- ma: presarcomatous factor? The idea that trauma may cause sarcomas has never been accepted without reluctance. There are cases, however, where the succes- sion of events follows the precise criteria set down in forensic medicine and leaves little doubt as to the correctness of the view that trauma may influence the development of tumors, probably in an indirect way by accelerating their hidden initial phase.

eL. DE LATI-IOUWER (Brussels): Presarco- matous conditions in sarcoma of the jaws Clinical and experimental data and the lit- e ra ture provide evidence of certain factors

Z. M. BACQ & P. MINET (Liege): Inci- dence of ionizing radiation on bone cancer's epidemiology. Importance of registra- tion of bone sarcoma The injection of high doses of a0Sr or of another "bone seeking" radioisotope causes


the appearance of bone sarcomas; the in- duct ion of leukemia by these injections is general ly less frequent. Since 1945 the bones of all vertebrates have been deposit- ing increasing amounts of 90Sr by the ab- sorpt ion (pulmonary and especially through the al imentary tract) of atomic fallout by- products originating from military tests (especial ly by the U S A and USSR). These tests were stopped in ].969, and fallout f rom the "reservoir" present in the strato- sphere has rapidly decreased and at the present is negligible; but the quantities of 90St f ixed in human bones are only now begin- ning to decrease significantly. The various technical reports of the U N S C E A R (United Nat ions Scientific Committee for Effects of A tomic Radiation), created in 1956 and present ly still active, offer a very large and precise documentat ion, originating in numerous countries (especially from the north- ern hemisphere), on the 90St levels and the 90St/Ca ratios in the bones and teeth of people of all ages. A hypothesis still main- ra ined by numerous radiobiologists and on- coiogists suggests that cancer induction by ionizing radia t ion is a phenomenon without threshold, strictly determined by the accu- mula t ion (without repair) of the damages caused to the nucleic acids, proteins, e t c . . . Being faced with the latency of ionizing radia t ion induced bone sarcomas (much longer than that of leukemia), it seems that the momen t has arr ived to focus part icular at- tent ion on the epidemiology of bone cancer, so that in 20 or 40 years the oncolo- gists should have at their disposal statistical da ta which will enable them to decide whether or not this hypothesis is defend- able. This study will become even more im- por t an t as the use of nuclear energy under- goes r ap id development, O0Sr being an acci- denta l pol lutant of certain types of reactors. P lu tonium is also localized in bone.

J. J. PINDBORO (Copenhagen): Clinical, ra- diographic and histoIogic aspects o) r JO cases o / j a w osteosarcomas In Denmark the incidence of sarcomas of the jaws is one per million per year. The 10 cases reported on are from the files of the Department of Oral Pathology, Royal Dental College, Copenhagen. F ive were males (average age 30 years) and five were females (average age 47 years). The mandible was affected in seven patients, the maxilla in three. The clinical and radio- graphic initial diagnosis was osteomyelitis in four cases, cyst in two, epulis in two, and tumorous ulceration in two cases. Six of the tumors were osteoblastic, three fibroblastic, and one chondroblastic.

J. BR~3oEro2 & C. Mmnnnu (Villejuif): Max- illofacial sarcoma and its frequency in tu-

mors of the maxillofacial region Between 1952 and 1973, 33 sarcomas of the facial region were observed at the Inst imt Gustave-Roussy. Twenty-three were found in the maxilla (but this still represents less than 5 % of mal ignant tumors of this region) and 10 were found in the mandible. Seventeen were in males and 16 in females. Twelve cases occurred in children; 10 in the 16- to 39-year age group and 11 cases in patients over 40 years of age. Histologic classification is difficult because different appearances are found in different areas of the same tumor. Furthermore, these appearances may change as the tumor devel- ops. I t may also be difficult to distinguish the real neoplastic component from reactive changes in the surrounding connective tissue. The histopathologist has three methods of naming these tumors: (1) malignant mesenchymoma (which covers our igno- rance), (2) to use a pure ly descriptive name for the different areas seen (e.g. histio-cyto- f ibro-xanthosarcoma), and (3) to describe the tumor by its most common component.


For the osteogenic sarcoma the problem is easier than for the fibroblastic sarcoma, which presents myoid, histioeytic, myxoid and angioid differentiation. Our material consists of 18 ehondrosarcomas, 10 fibrosarcomas, two osteosarcomas, two histio- cyto-fibrosareomas and one invading fibroma. The radiologic appearances are variable. When first seen, no patient had cer- vical lymphadenopathy or any metastases, Twenty-nine patients were given a complete excision followed in 15 cases by irradiation. Two patients were treated by irradiation only and two patients were not treated. The total survival was 55 % after 3 years; 44 % after 5 years and 3 i % after 10 years. Of 22 patients who died, local recurrence was present in all cases. Five patients had distant bone or pulmonary metastases. No patients with mandibular neoplasms survived for 5 years.

cases. Two patients had a history of irradiation. There is no significant difference in the sex rate or localization. The average age is 41 years. Swelling is a constant and pain a frequent finding. Finally, the first clinical symptoms simulate dental pa in in half of the cases. The radiologic findings are frequently osteocondensing or mixed. The radiologic presumption of malignancy was found in only two cases. Two patients had metastases. The initial treatment consisted of extensive surgical resection asso- ciated in some cases with radiotherapy. Re- mission was short. Recurrences were treated by irradiation or chemotherapy exclu- sively or in association with surgery. Seven of 13 patients were alive after 2 years and three out of 11 after 3 years. No patients survived 5 years. Three patients are alive without recurrence, 2, 30 and 50 months after treatment.

eL. DE LA.THOUWER, N. DOUROV, R. HEr- ~AN, Z. HORANYI, P. POT~gLtECE (Brussels), M. A. DELVmNE. (Liege), C. FmvEz (Lover- val) & H. Rom.s (Gent): Analysis of 15 cases of so-called osteogenic sarcoma of the law The analysis of the materiaI coming from different Belgian centers and flied in the Register of the Group ol~ Maxillofacial Bone Pathology has given 13 osteosarcomas. They have been eIassified according to histologic differentiation: five osteoblastic osteosarcomas, six chondroblastic osteosarcomas and two fibroblastic osteosarcomas. Furthermore, there were two fibrosarcomas. WHO criteria were used for classification and terminology. Three cases were rejected (fibrous dysplasia, osseous sequestrum, des- moplastie fibroma). Three fibrous lesions with a controversial diagnosis were not included. Of the 15 cases studied, the correct diagnosis was suggested initially in only six

WILLIAM H. BINNIE (London): Sarcomas of the law: analysis o/ cases fi'om the South Metropolitan Cancer Registry Forty-three cases were registered between i958 and 1970. Twenty-four of these were from within the region served by SMCR, which is a population area of approximately eight million. The annual_ incidence is therefore very low, 1 per 5 million persons. Data recorded in the 43 cases included age, sex, site, histologie diagnosis, treatment and follow-up. Thirty-six intraosseous sarcomas included osteosarcoma (16), fibrosareoma (7), chondrosarcoma (4), chondromyxofibro- sarcoma (2), Ewing's sarcoma (1) and un- specified sarcoma of bone (6). Other cases recorded were synovial sarcoma (1) and re- tieulosarcoma of bone (6). Lesions of the mandible were three times more common than those of the maxilla and males were affected twice as often as females. Eleven cases were treated by surgery, eight by ra-


diotherapy and 21 by a combination of the two. The survival curves of 36 patients with the intraosseous lesions show that 40 % were still alive after 5 years and 27 % after 3.13 years.

P, CERNI~A, J. PA~/EN & eL. BROCHERIOU (Paris): Bone sarcomas of the laws: statistical study of 41 observations During a 20-year period at the Institut de Stomatologie de la Salpetriere (Paris), 41 bone sarcomas were observed among a total of 585 jaw tumors, including 61 sarcomas. Eighteen were osteosareomas, 7 chondrosarcomas and 16 fibrosarcomas. Osteo- sarcomas of the jaws occur in a slightly older age group than those in other sites and have a better prognosis (25 % survive 5 years). In contrast, chondrosarcomas appear earlier, most frequently in the maxilla, and have a poor prognosis (not one case survived 7 years). Fibrosarcomas have the best prognosis of all (nearly 50 % surviving 10 years). Among these 41 hone sarcomas, five appeared in jaws previously irradiated (four osteosarcomas and one fibrosarcoma) and one osteosarcoma occurred in a mandible with Paget's disease.

H. E. SIMPSON, D. JACKSON & I. RaNNIE (Newcastle upon Tyne): Experience of sarcoma of the jaws at the Newcastle upon Tyne Denta l School and Hospital Sarcoma of the jaws is a rare condition among our clinical patients, occurring in perhaps one in 40,000. However, specimens are also sent to us for histologic examina- tion and we are able to present, in aU, 14 eases. Fou r are fibrosarcomas, three osteosarcomas, four chondrosarcomas, and three miscellaneous types which are included for completeness. Ten of the tumors were ap-

parently of endosteal origin, one was parosteal, two probably periosteal, and one in- determinate. The tumors were equally distributed between the sexes and covered a wide age range, the youngest being 9 years old and the oldest 75. Six occurred in the maxilla and eight in the mandible. Treat- ment was by surgery, radiotherapy or both, and two also received cytotoxic drugs. Sur- vival was very variable; some patients lived for a number of years, but most died with recurrence or metastases even after as long as 7 years. Six lived for 2 years or less.

P. BERTOIN, M. BRUNAT & M. FREIDEL (Lyon): Osteosareoma of the mandible: & surgery defensible? Eight cases of sarcoma of the mandible are described, some treated as long as 12 years ago. The youngest patient was 2 years old and the oldest was 71. Two were chondrosarcomas, four fusocellular sarcomas, one myxosarcoma and one polymorphous sarcoma. Four patients are still alive without recurrence or metastasis. Six patients had a mandibular ~ resection and four of those died 1.-4 years after surgery. Two cases were irradiated and were later treated with chemotherapy; both are still alive, one after 1 year and the other after 1.2 years. It seems difficult to decide purely on the basis of radiologic and histologic criteria when surgery should be the treatment of choice. The age of the patient and the clinical appearance of the tumor would appear to be more important in deciding the type of treatment.

R. REGNIER (Brussels): Radiotherapy of sarcoma of the osteogenic series of the )r ciaI bones The literature is imprecise regarding the


value of radiotherapy in the treatment of sarcomas of the facial bones. These are rare tumors and only nine patients were treated between 1.947 and 1970 at the Bordet Insti- tute of Brussels. The success of local irradiation to the lesion is minimal and often if combined with ~hemotherapy is useful only as a palliative measure. Irradiation of postoperative recurrence may not even reduce pain due to the extension of the tumor and even after a complete resection has no better chance of cure. The high dose necessary for treatment would not allow postoperative healing of the tissues. Radiotherapy would seem to be most useful preoperatively. The frequency of local recurrence even after a wide resection justifies the attempt to ster- ilize the tissues at the margin. Cases have been described in which combined surgery and radiotherapy have provided exception- ally high recovery rates.

F. J. L~aEUNE (Brussels): Evidence for im- munologic reactions and viral involvement in sarcoma In 2964 the appearance of antibodies was followed by a prompt rejection of homo- transplants of cultured human osteosareoma cells and we were able to show a total dis- appearance of lung metastases in one out of four patients treated with repeated injections of similar ceils. The cured patient was

coma. The evidence for common antigens and for viruses in human sarcoma opens new prospective ways for the immunotherapy of these highly malignant tumors.

C. DECKERS, J. I-{ERMANS, J. [LoNGUEVILLE & H. MAISIN (Louvain): Chemotherapy and immunotherapy as adjuvant treatment of sarcoma of the maxilla

Osteosarcoma of the jaws has a slightly better prognosis than other skeletal sites. Dis- tant metastases are less frequent but nevertheless are responsible for about 50 % of the treatment faitures. This justifies the use of adjuvant treatment after surgical excision and irradiation. After surgery and irradiation, we give these patients courses of chemotherapy (Oncovin| Aetinomycin| Endoxan| alternating with non-specific immunotherapy (BCG treatment).

A. CASTERMANS, A. VAN GARSSE & R. WiN WIJC'K (Liege): Reconstruction of the mandible alter resection [or oral cancer

Thirty-seven cases of TaNoM 0 or T,.~_ aNtM0 squamous cell carcinomas of the lower half of the oral cavity were treated by resection arid radical neck dissection. The continuity of the mandible was restored by a threaded wire. The 5-year survival rate was .56 and the overall 3-years' tolerance of the wire was .38. Thns, the wire technique can be considered a valuable yet temporary meth- od of reconstructing the mandible. The tolerance of the wire has been studied in par- ticular.

M. BE~rOIST (Paris): Repairing the mandible after ablative surgery The mandible must be reconstructed after


surgical removal of a tumor which has caused dis turbance of the occlusion or the facial appearance. Successful reconstruction depends on respecting certain conditions. These are: (1) the replacement specimen must be of the same dimension as the piece of mandib le removed, (2) fixation must be solid, (3) skin and muscle must be replaced to ensure good protect ion for the graft. We are using two types of endoprosthesis: (1) a metal-plast ic type to replace a bony seg. ment, and (2) a grooved metal type. Recon- struction is assured by a graft from the hip which is held in posi t ion by the prosthesis and guarantees solidi ty during healing. So far we have done 219 reconstructions; 124 with the metal-plast ic prostheses and 95 using bone grafts.

J. J. KRUISBRINK (Amsterdam): Principles of immediate prosthetic closure of maxil- lary defects following cancer surgery Trea tmen t of mal ignant tumors, part icular- ly in the maxilla, calls for the close cooper- a t ion of medical specialists and the pros- thodontist . Inconvenience to the patient can be minimized by working according to the following principles. A n optimal prosthetic result calls for prevention of wound con- traction and forming of stress-bearing areas and re tent ion zones. The surgical defect is filled immedia te ly with an obturator appli- ance which serves as a support for a ther- moplas t ic mater ia l to which a split skin graf t is attached.

G. B. SNOW (Amsterdam): Reconstruction and rehabilitation after mandibulectomy for cancer Because of improved methods of recon- s truct ion more radical resections are now being done. The reconstruct ion program is:

fixation of the mandibular stumps by inter- maxil lary splinting. Three months later the mandible is restored with art iliac bone graft. Five months after resection the inter- maxil lary fixation is removed if there seems to be sufficient consolidation of the graft. One or two months later buccal and lin- gual sulci are restored by skin inlay grafts.

Odontogenic tumors

J. J. PINDBORG (Copenhagen): Terminology and classification of odontogenic tumors In 1971, the W H O published the "Histo- logical Typing of Odontogenic Tumours, Jaw Cysts, and Allied Lesions" after 11 centers in 9 countries bad worked for 5 years. To judge from the literature, the classification appears to be used in a number of countries. The classification, which is based upon the interrelationships of dental tissues, uses a terminology which is consistent with results of recent research. Thus, terms like adenoameloblas toma and melanoamelobla- stoma have been abandoned. The speaker suggested using the classification for anal- yses of materials of odontogenic tumors. I t is hoped that a revision of the classification will be undertaken after 5 years.

I. R. H. KRAMER (London): Morphologie variations of ameIobIastomas The ameloblastoma is an uncommon tumor that occurs predominant ly in the mandible, usually as an intraosseous lesion. There are two basic patterns, the foll icular and the plexiform. In the foll icular type the tumor epithelium appears to be arranged in is- lands in a fibrous strorna, whilst in the plexiform type the epithelium is arranged as a continuous network. However, both pat terns may be present in a single tumor,

SYMPOSIUM ON MAXILLOFAC[AL BONE PATHOLOGY 89

and tumors showing either pat tern appear to have the same clinical behavior. In the follicular type, cysts develop within the epithelium; in the plexiform type the cysts are usually in the stroma. Variants of the ameloblastoma include the acanthomatous, granular-celled and spindle-celled types: juxtaepithelial hyalinization, keratinization and calcification may also be seen, especially in the follicular type. The fibroameloblastoma (ameloblastic fibroma) is probably a true mixed tumor, consisting of odontogenic epithelium and odontogenic mesoderm (mesectoderm). Both the fibroameloblastoma and the odontoameloblastoma may show true inductive changes. MMignant ameloblastoma is very rare, as is the malignant form of the f ibroameloblastoma: the latter is a sarcoma with a benign epithelial component. The ameloblastoma infiltrates the spaces of can- cellous bone but does not penetrate the Haversian canals of compact bone. Thus, in compact bone the apparent margin of the tumor is likely to be the true margin. In areas of bone expansion, the tumor may involve the periosteum, and subperiosteal resection in such areas may lead to recurrence.

majori ty of calcifying odontogenic cysts behave like odontogenic cysts, i t is possible to distinguish four different types of odontogenic tumors which may occur in combination with the cyst. These are: a dentinoid producing type of ameloblastoma, the odontoameloblastoma, the amelobIastic fibro-odontoma, and the complex odontoma. Among the 19 cases studied, nine were combined with one of the four types of odontogenic tumors mentioned. The re- maining 10 cases were genuine cysts. Al l but one, an eruption cyst in an infant, showed characteristic proliferat ions of odontogenic epithelium and format ion of dentinoid in the cyst wall.

J. B. DE GANDT, ~V[. GERARD 6% ]~. ]-c-][ENNE- BERT (Brussels): Ameloblastoma of the ma- xillary sinus A 44-year-old man living in Zaire presented because of discomfort in the left maxi l la ry tuberosity. Examinat ion showed an oroan- trat fistula filled with congestive tissue. Bi- opsy proved this tissue to be an ameloblastoma. Fronta l and profile tomograms showed the tumor to be in the maxi l lary sinus. The tumor was resected.

F. ~RAETORIUS (Copenhagen): Calcifying odontogenic cyst: range, variations and neoplastic potential Since the earliest descriptions of the calcifying odontogenic cyst it has become evident that the lesion is more complicated than was first assumed. Based on a study of nine calcifying odontogenic cysts registered in Copenhagen and 10 more cases contributed by the investigators of the WHO Group on h~ternational Histological Classi- fication of Odontogenic Turnouts, Jaw Cysts and Allied Lesions, it appears that the cyst may be combined with different types of odontogenic tumors. Although the

P. CERNgA, J. IaAYEN, CL. BR0C~IERIOU & A. MAZABRAUD (France): Malignant odontogenic tumors Nine cases of malignant ameloblas tomas are reported. Al l have shown mult iple recurrences but with long intervals of remis- sion. Three cases, which had been widely excised, eventually recurred in the internal pterygoid muscle and floor of mouth and involved the skin. Two were more aggres- sive. One spread in the pterygopalat ine and temporal fossae and the other involved the mental nerve, with sequestration. F o u r


cases p roduced bilateral lymphatic involvement. The histologic diagnosis is difficult, and some cases which show a pseudoglan- dular appearance may be int ramandibular sal ivary carcinomas, al though the clinical appearance and behavior are characteristic of ameloblastomas. A description is also given of an ameloblast ic sarcoma in a young woman 10 years after numerous cur- rettings and rad io therapy of an ameloblastic f ibroma. Lastly, a carc inoma in the wall of a dentigerous cyst was resected from the mandible of a child. Fif teen years later the pat ient is still free of tumor.

A. VERttEST & CL. DE LATHOUWER (Brus- sels): Malignant primary intraosseous carcinoma o / t h e mandible: report o] a case A case of pr imary intraosseous carcinoma of the mand ib le in a 67-year-old man is described. This very rare tumor probably originates f rom the epithelial rests of Ma- lassez or f rom the fusion of the facial em- bryonic buds. Clinical signs are not specific. This ca rc inoma occurs predominant ly in the sixth or seventh decade. The mandible is the preferen t ia l site. The differential diagnosis is made histologicaUy by excluding (a) the neoplast ic t ransformat ion of odontogenic cysts, (b) mucosaI squamous carcinoma extending into the bone, (c) malignant ameloblastoma, and (d) distant metastases of visceral neoplasms to the jaw. The prognosis of the tumor regardless of type of t rea tment is evaluated at 30 to 40 % survival af ter 5 years. The absence of metastases improves the prognosis. In the present case the t rea tment consisted of administrat ion of cobal t i r rad ia t ion (4,500 rads deep) and be- t ra ton (2,250 rads deep). This reduced the symptoms bu t could not prevent death 1 year af ter the appearance of Iocal recurrence.

A. K. PANDERS (Groningen): Cementum producing taw tumors and allied lesions The lesions containing cementum-like tissue form a complex group with ill-defined characteristics. It is especially difficult to give a precise description of the cementi- fying fibroma. Out of 110 fibro-osseous- cemental lesions, 38 could not be classified according to the scheme given in the Inter- nat ional Classification of Odontogenic Tu- mours, No. 5, 1971.

N. DOUROV (Brussels): Recurring cementi- /ying ]ibroma with involvement of the tooth A case is reported of a fibrous tumor which occurred after extraction of a nmxillary third molar. The tumor contained cementum and bone and appeared at the extraction site. It has recurred three times in 4 years. The pathogenesis of this lesion is un- known and it is possible that t rauma may have contributed, involving the mult iple po- tentiality of the alveolar dental ligament.

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R. B. LUCAS (London): lntraosseous salivary tumors Although not common, salivary tumors present as intraosseous lesions often enough to warrant consideration in the differential diagnosis of tumors of the jaws. The possible origins of these neoplasms include salivary glandular tissue within the jaws or within bony defects and odontogenic epithelium. The commonest type of lesion is the mucoepidermoid tumor, which accounts for one-half of all the cases of intraosseous salivary tumors. Adenoid cystic carcinoma is the next most frequently occurring tumor, followed by pleonaorphic adenoma. Single cases of various other types of salivary tumor have also been reported. Defin-


itive preoperative diagnosis is difficult; the clinical and radiologic features may suggest dentigerous or dental cyst, ameloblastoma or other tumors, or even fibrous dysplasia. The microscopic diagnosis carl be readily made in tumors showing typical features, but the appearances may on occasion be unusual, in which case diagnostic difficul- ties may arise.

A. D. BEYNON (Newcastle upon Tyne): Giant cell lesions o[ the ]aws: histologtc and histochemical aspects Giant cell lesions of the jaws - including giant cell granuloma (GCG), cherubism, and brown tumor of hyperparathyroidism - comprise a heterogeneous group of clinico- pathologic entities, l inked only by their dis- tinctive histopathology and resembling one another very closely. Several studies on pri- ma ry hyperparathyroidism have shown that brown tumors may occur in the jaws as a presenting sign; furthermore, these lesions are frequently misdiagnosed, being treated by curretage or even irradiation before the proper diagnosis is made. The histogenesis of these lesions is uncertain; most authors concur with JAFFZ that they arise from non- osteogenie tissues, representing an abnormal reparative response to injury. This hypothesis will be re-examined in this paper. Non- enzymatic and enzyme histochemistry (in- eluding oxidases, and lysosomal acid hydro- lases) was carried out on one case of cherubism, six cases of GCG (three central, three peripheral) and one case of brown tumor of the jaw. Additionally, non-enzymatic histochemistry was performed on two further cases of G C G and four cases (two in the jaw) of brown tumors. The giant cells showed marked oxidative and lysosomal enzyme activity, closely resembling osteociasts. Acid hydrolase techniques re- vealed that the stromal cells comprised two

separate populations, namely phagocytes and fibroblasts. Furthermore, acid hydro- lases are unequally distributed between phagocytes and giant cells. There was no evidence of phagocytosis by giant cells, par- ticularly of blood breakdown products. No distinction could be made between the brown tumor and the other lesions. Since the brown tumor is a direct consequence of high levels of circulating parathormone (PTH) undergoing repair on reduction of PTH to normal levels, the action of PTH will be reviewed. Apar t from its effects on kidney and gut, the only known effect of PTH on bone is to induce osteoclasts (and possibly osteoblasts) from osteogenic tissues. These various observations are interpreted as providing support for the older hypothesis of histogenesis of giant cell lesions from osteogenic tissues, the giant cells being abnormal osteocIasts.

CL. BROCHERIOU, F. GUILBERT & C. Rou- CHON (Paris): Ewing's sarcoma in the man-

dible: report of two cases Among 6I jaw sarcomas studied at the In- stitut de Stomatologie de Paris, two Ewing's sarcomas of the mandible have been de- tected; one is in a 9-year-old girl, the other in a 16-year-old boy. They were treated by combined chemo- and cobalt therapy, then by mandibular resection when the tumor recurred. In one case death occurred rapidly after 10 months because of consider- able local extension. The other case has survived longer. After the appearance of the first symptoms 4 ~ years ago, a relapse is relatively well controlled by chemotherapy.


European Registry of Malignant Maxillo-Facial Bone Tumours

The par t ic ipants at the Symposium on Max- i l lofacial Bone Pathology have concluded that intensive international co-operation is necessary in the field of malignant maxillofacial bone tumors and they have decided to establish a European Registry.

I t is hoped eventually to establish treatment schemes.

The Technica l Secretary and the Registry Center are in Brussels.

Al l interested persons wishing to co- operate in the Registry scientifically, tech-

nically or by sending cases are invited to contact Dr. CL. DE LATItOUWER, 14, rue de la Tour Japonaise, 1120 Brussels or Dr. CL. BROCHEglOU, Institut de Stomatologie, H6- pital de la Salp~tri~re, Bd. de l 'H6pital , 47, Paris. Dr. I. R. H. KRAMER, Institute of Dental Surgery, Eastman Dental Hospital, Gray 's Inn Road, London WC1X8LD. Dr. A. K. PANDERS, Mondheelkunde, Akade- misch Ziekenhuis, Groningen. Dr. J. J. PINDBOR6, Royal Dental College, 4, Uni- versitetsparken, DK 2100 Copenhagen.

symposium on maxillofacial bone pathology

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