Myxosarcoma

Myxosarcoma on the left thigh of an 11-year-old, female Poodle. These tumours of mesenchymal origin usually present as neoplastic proliferations of fusiform cells, separated by an abundant mucinous matrix. Note the cystic appearance of this apparently encapsulated mass, filled with numerous nodular formations and containing a large amount of mucoid viscous fluid. The highly infiltrative behaviour of this kind of neoplasia makes its complete surgical removal extremely difficult, this being the main reason why the probability of recurrence is so high.