High-grade angiosarcomas (HGAS) of bone are rare and represent less than 1% of the primary malignant bone tumours. Because of their rareness little is known. Clinically, it is accepted that they are extremely aggressive. Due to the lack of uniform terminology and accepted histological criteria, terminology and classification of primary malignant vascular tumours of bone has been highly controversial. Today, angiosarcoma is the most accepted term for high-grade primary vascular tumour of bone, recognized by the 2002 WHO Classification. However, distinct histological hallmarks to define a HGAS of bone are not clear.

We collected 64 HGAS of bone diagnosed between 1964 and 2007 from the files of the departments of pathology, Leiden University Medical Center (Leiden), Rizzoli Institute (Bologna) and University Hospitals (Leuven). All clinical, radiological, and pathological data were reviewed and different histological criteria were scored. A tissue micro-array was constructed containing 57 HGAS of bone. To confirm the vascular origin of all lesions and to investigate the diagnostic value of commonly used markers, immunohistochemistry was performed for CD31, CD34, Factor VIII, and keratin AE1/AE3. Staining was evaluated positive or negative.

Among 64 patients with HGAS of bone, there are 41 males and 23 females. There is a wide age distribution, with a nearly equal distribution from the second to the sixth decade. The solitary cases are mostly located in the extremities (66%) followed by trunk (12.8%), axial/central location (10.6%) and pelvis (10.6%). 17 cases (73%) have multifocal bone lesions. HGAS of bone show variable histological patterns. Association with clinical outcome (chi-square test) reveals that there is a significant poor survival when the tumour has tree or more mitoses (p=0.001), a macronucleoli (p=0.011) or there is an absence of an eosinophilic infiltrate (p=0.023). The HGAS of bone are positive for CD31 in 53/55 (96%), CD34 in 33/57 (58%), Factor VIII in 47/55 (86%), and keratin in 40/57 (70%). Only 15 out of 40 (38%) keratin positive angiosarcomas, showed an epithelioid phenotype at classical morphology. All tumours with an epithelioid phenotype are keratin positive.

Although HGAS of bone in general have a poor outcome, histological criteria such as three or more mitoses, the presence of a macronucleolus and the absence of an eosinophilic infiltrate can be useful to predict a more aggressive course, consistent with the clinical behaviour of a high-grade angiosarcoma. CD31 and Factor VIII are the best diagnostic markers for HGAS of bone. It is striking that keratin positivity is seen in the majority of cases, and is independent of epithelioid morphology. Pathologists should be aware of this to avoid misinterpretation as metastatic carcinoma.

Introduction: The role of surgery for local control in the multimodal management of Ewing’s sarcoma has substantially increased during the past 20 years. However, selection bias due to location (extremities vs axial skeleton) and relatively non-homogeneous treatment received by patients in multi-institutional trials may limit objective evaluation and comparison of the relative role of surgery and radiation therapy in this setting. Purpose of this study was to review a large series of patients homogeneously treated at a single institution.

Methods: 268 patients with non-metastatic Ewing’s sarcoma of the extremities treated by contemporary multimodal management were reviewed. Chemotherapy was administered according to 4 sequential protocols of adjuvant (1) and neoadjuvant (3) treatment. Local control consisted of surgery in 136 patients, surgery and radiation therapy in 70 patients, and radiation therapy in 60 patients. Two patients underwent only chemotherapy.

Results: The 5-year event-free survival (EFS) and overall survival (OS) were 62 and 69 per cent respectively. The rates of 5-year EFS and local control were significantly lower in patients treated with radiation therapy compared to patients treated by surgery or surgery and radiation therapy (48 vs 66 per cent, p=0.002; 80 vs 94 per cent, p= 0,0001). In group 3 (Radiation Therapy only) there were also 6 secondary malignancies.

Conclusion: Surgery was associated with better survival and local control in this series. In our opinion, surgery should always be considered in the local treatment of Ewing’s sarcoma of the extremities. Postoperative Radiation Therapy must be added in cases of inadequate surgical margins.

Aims: Purpose of this study was to obtain long term follow-up in patients with Osteofibrous Dysplasia (OFD), in order to investigate natural history of the disease, late results of treatment, and potential risk of Adaman-tinoma development in this setting. Methods: A retrospective study of 48 patients with histologically proven OFD observed at our Institution between 1900 and 1997 was undertaken. Clinico-pathologic features of all cases were reviewed and found consistent with OFD. A clinical status update and current radiographs were obtained in all patients. A subgroup of 21 patients with minimum follow-up of 20 years (21 to 44 years, average 27) was analysed for functional result and adamantinoma development. Functional result according to MTS-ISOLS score correlated with surgical aggressiveness. Results: Best results were observed in patients that received a single biopsy or curettage; worse results were seen after multiple resections or osteotomies and associated with complications as infection or compartment syndrome. No patients had current symptoms or significant symptoms changes nor physical findings, radiographic clues or subsequent radiographic changes suggesting adamantinoma development. Conclusions: OFD is a benign condition; the natural history of the disease has minimal consequences in the adult life. Surgical treatment is usually not necessary and may actually worsen the result because of the potential for severe complications.

The relationship with adamantinoma remains unclear, follow-up is suggested.