Atypical lipomatous tumour

An atypical lipomatous tumour is a locally aggressive mesenchymal neoplasm in which the adipocytes show significant variation in cell size and have some nuclear atypia. These tumours are at risk of local recurrence. In the extremities or trunk the term atypical lipomatous tumour is justified as complete excision is usually curative and local recurrence manageable. In the retroperitoneum or mediastinum however, tumours with the same biological composition are difficult to completely remove and can recur with disastrous consequences for the patient. In these locations, the term “well-differentiated liposarcoma” may therefore be more appropriate.

Atypical lipomatous tumours account for 40-45% of all liposarcomas and occur predominantly in middle aged adults, peaking in the sixth decade. They most frequently occur in the deep soft tissues of the limbs, especially the thigh, but may also occur in the retroperitoneum or paratesticular area. Tumours often grow slowly, are painless and can achieve significant sizes.

Anatomical location is the most important prognostic factor. Lesions in surgically resectable sites tend not to recur after complete excision. In more difficult anatomic sites, incomplete excision is associated with local recurrence, which in turn can lead to loss of local control, or be associated with dedifferentiation and death. The risk of dedifferentiation is said to be over 20% in the retroperitoneum, but <2% in the limbs.

1. WHO Classification of Tumours of Soft Tissue and Bone. 4th Edition, 2013.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s