Fibrosarcoma of the jaws.

The records of 14 patients with fibrosarcoma of the jaws--10 in the mandible and four in the maxilla--from the files of the Netherlands Committee on Bone Tumours were studied. The mean age of the patients was 30 years; more men than women were involved; pain and especially swelling were the symptoms most frequently present. The radiographic appearance often indicated the malignant nature of the lesion. Histologically 42% of the tumours were low-grade malignant. The 5-year survival rate was 71%, which is more favourable than either fibrosarcoma located elsewhere in the skeleton or osteosarcoma of the jaws. Radical surgery is the therapy of choice. All cases with an unfavourable course acquired lung metastases.

Fibrosarcoma of long bones. A study of the significance of areas of malignant fibrous histiocytoma.

A study was made of the clinical course of 102 cases of fibrosarcoma of long bones. Of these, 55 were predominantly fibroblastic or pure fibrosarcomata while 47 contained extensive areas resembling so-called malignant fibrous histiocytoma (MFH). Treatment was similar in the two groups, and the five-year survival was the same, 34%, in both groups. Lung metastases developed in 63% of the fibroblastic sarcomata and 59% of the MFH-like tumours. Our study indicates that there is no significant difference in behaviour in fibrosarcoma with or without marked MFH features. The histological grading of both groups of fibrosarcomata together was of prognostic value; five-year survival was 64% in 14 Grade I tumours, 41% in 32 Grade II tumours and 23% in 56 Grade III tumours.

Giant cell tumour: metaphyseal or epiphyseal origin?

The question whether giant cell tumours (GCT) of tubular bones originate in the metaphysis or epiphysis, was investigated by studying 233 GCT registered in the files of the Netherlands Committee on Bone Tumours. In 6 cases the GCT was found to be located in the metaphysis exclusively, no case with a purely epiphyseal localization was found. The result of this study favours the metaphyseal origin of GCT. An unusual case is discussed.

Aneurysmal bone cysts: a clinicopathological study of 105 cases.

A clinicopathological review of 105 cases of aneurysmal bone cyst is reported. Age and sex distribution and localization were in agreement with two previously reported large series. Recurrence occurred in 30.5% of all the cases and in 34.2% of those treated by curettage. Proved incompleteness of surgical removal was an important factor in recurrence (12 out of 17 cases or 70.6%). The recurrence rate was significantly (P2 less than 0.01) higher in cases with a mitotic index of seven or more per 50 fields (X 750) than in those with a lower mitotic index. In relation to the recurrence rate, no statistically significant differences were found between the age groups less than or equal to 15 and greater than 15 years, between the combination age and lesion size, or between four localization groups. The cyst wall and the septa consist of a superficial layer of cellular fibroblastic and histiocytic tissue in which multinuclear giant cells are present, covering a deeper situated zone of less cellular fibrous tissue. This typical layered architecture was found at one or more places in 93 (88.6%) out of 105 cases. However, layered architecture may also be found in cases of teleangiectatic osteosarcoma. It is suggested that the group with a high risk of recurrence be treated more radically, i.e., with cryosurgery.

Aneurysmal bone cyst and telangiectatic osteosarcoma. A histopathological and morphometric study.

In a series of 105 cases of aneurysmal bone cyst, 18 showed an unusually high level of mitotic activity and/or increased nuclear pleomorphism which complicated the differential diagnosis with respect to telangiectatic osteosarcoma. An attempt was made to use semi-automatized morphometric and histophotometric techniques to establish objective morphological differences between these unusual cases of aneurysmal bone cyst and 16 cases of telangiectatic osteosarcoma. Three cases (two of aneurysmal bone cyst and one of telangiectatic osteosarcoma) proved unsuitable for analysis. In 24 of the remaining 31 cases (77%) a computerized discriminant analysis permitted correct discreimination with a high degree of certainty on the basis of quantitative nuclear characteristics determined in paraffin sections. In the other 7 cases the diagnosis was less certain (3), doubtful (2) or erroneous (2). The relevant nuclear characteristics were (in ascending sequence of discrimination): the largest nuclear surface area, the mitotic index, and the percentage of nuclear sections exceeding an arbitrarily chosen limit of 60 micron2. The criterion of nuclear size for discrimination between these benign and malignant lesions could be applied for two reasons: firstly, because a group of extremely large nuclei occur in malignant cases, and secondly, because the average nuclear size is larger in malignant than in benign lesions. The extremely large nuclei occur as only a small percentage of the total nuclear population. The other variables investigated, i.e., cellularity and nuclear contour ratio, did not contribute greatly to the differentiation. In 11 cases, the average nuclear Feulgen extinction was estimated as an additional variable.