Mediastinal lymphoma

Mediastinal lymphoma in a mixed breed dog. This large mass, roughly 14 by 5cm, with an irregular surface, friable consistency and lardaceous cut surface, completely occupied the mediastinum, compressing the thoracic organs. Several smaller pleural metastatic nodules could also be seen adhering to the parietal pleura, which lines the inner surface of the thoracic walls. This type of metastasization process is named trans-coelomic and occurs through direct contact of the primary tumour with the surface of other organs contained in the same coelomic cavity.