Of 3000 patients diagnosed with primary malignant bone tumours and treated at our unit over the past 25 years, 234 (7.8%) were considered to be spindle cell sarcomas of bone (ie not osteosarcoma, chondrosarcoma, Ewing’s, chordoma or adamantinoma). We have analyzed their management and outcomes.

The diagnosis of these cases varied with fluctuations in the popularity of conditions such as MFH, fibrosarcoma and leiomyosarcoma with the passage of time. Treatment was with chemotherapy and surgery whenever possible. 36 patients had metastases at diagnosis and 17 had palliative treatment only because of age or infirmity. The most common site was the femur followed by the tibia, pelvis and humerus. The mean age was 45 and the mean tumour size 10.2cm at diagnosis. 25% of patients presented with a pathological fracture. Chemotherapy was used in 70% of patients the most common regime being cisplatin and doxorubicin. 35% of patients having neoadjuvant chemotherapy had a good (> 90% necrosis) response. The amputation rate was 22% and was higher in patients presenting with a fracture and in older patients not having chemotherapy.

With a mean follow up of 8 years the overall survival was 64% at 5 yrs and 58% at 10 yrs. Adverse prognostic factors included the need for amputation, older age and poor response to chemotherapy as well as a pathological fracture at presentation. The few patients with angiosarcoma fared badly but there was no difference in outcomes between patients with other diagnoses.

We conclude that patients with spindle cell sarcomas should be treated similarly to patients with osteosarcoma and can expect comparable outcomes. The histological diagnosis does not appear to predict behaviour.

Background: ASPS is a rare, high grade sarcoma primarily affecting children and young adults. Its origin remains enigmatic and there has until recently been no diagnostic markers. Diagnostic problems particularly occur when presenting as metastasis before detection of the primary tumour and when there is morphologic overlap with other malignancies. Recently, identification ASPS/TFE3 fusion transcripts and immuno-detection of TFE3 have been reported as useful diagnostic tools.

Design: 17 ASPS were analysed in terms of clinicopatho-logic characteristics, treatment and follow up. Archival formalin-fixed and paraffin embedded tissues were used for TFE3 immuno-histochemistry and RNA extraction followed by RT-PCR analysis and sequencing. Novel primers to detect ASPS/TFE3 fusion transcripts, type 1 and 2, were designed.

Results: The patients, 9 females/8 males, ranged in age from 3 to 46 years (median 23 years); 16 involved the extremities (9 lower, 7 upper) and one the pelvis. All but one patient had primary, curative surgery; chemotherapy and radiotherapy was given for metastatic disease. Five had lung metastases at diagnosis and 3 developed lung and brain metastases later. Four patients died of disease (after 1–5 years), 4 are alive with metastases and 9 are alive and well (after 6 mos.-10 years). 15/15 ASPS showed ASPL/TFE3 fusion transcripts (8 type 1, 7 type 2) and TFE3 immuno-positivity. Of 26 control tumours, several of which with overlapping morphologic features, none had fusion transcripts, 4 showed immuno-positivity (all granular cell tumours).

Conclusions: Immuno-detection of TFE3 and RT-PCR based identification of ASPL/TFE3 fusion transcripts in formalin-fixed/paraffin embedded tissues are powerful tools in the diagnosis of ASPS.