Browsing by Author "Åström, Max"

INTRODUCTION: Differentiating atypical lipomatous tumours (ALT) and well-differentiated liposarcomas (WDLS), also known as grade 1 liposarcomas (G1LS), from benign lipomas is a common diagnostic problem for pathologists. ALT/WDLS are characterised by amplification of the murine double minute 2 (MDM2) gene and our aim was to investigate if immunohistochemistry for MDM2 can be used to diagnose ALT/WDLS. We also reported treatment and calculated survival rates for patients with grade 1 liposarcomas (G1LS) at Helsinki University Central Hospital (HUCH). METHODS: 25 lipomas, 17 ALT and 21 G1LS were reviewed and initiated for MDM2 immunohistochemistry. For the clinical cohort we included 53 patients with a final diagnosis of G1LS during 1995-2007. RESULTS: The sensitivity of MDM2 immunohistochemistry for ALT and G1LS was 35% and 86%, respectively. The specificity in distinguishing ALT and G1LS from lipomas was 100%. The 5-year local-recurrence free survival (LRFS) for G1LS was 80%, and the 10-year LRFS was 68%. Local recurrence occurred in 16/53 patients. Retroperitoneal and intra-abdominal tumours had a 4.224 times greater risk of local recurrence compared to tumours in the extremities or trunk wall. Only one patient died due to G1LS. DISCUSSION: MDM2 immunohistochemistry is a good supportive method when diagnosing lipomatous tumours. It was highly specific in differentiating ALT and G1LS from lipomas and also relatively sensitive in recognising ALT and G1LS. We reported that G1LS are recurring tumours with tumour site strongly affecting the risk of local recurrence. Despite the high risk of local recurrence, the mortality of G1LS is low.