SONOGRAPHIC FINDINGS IN HORSES WITH MEDIASTINAL LYMPHOSARCOMA - 13 CASES (1985-1992)

Sonographic findings correlated with necropsy findings in 8 of 9 horse s in which the cranial portion of the mediastinum was evaluated by use of both methods. Cranial mediastinal masses were imaged as multilobul ar and homogeneously hypoechoic; a complex echogenic pattern was obser ved with necrosis within the mass. Pleural effusion was a common findi ng in horses with mediastinal lymphosarcoma. Cytologic evaluation of p leural fluid samples was useful in diagnosis of lymphosarcoma in 10 of 12 horses that had thoracentesis. Sonographic examination of the thor ax and cranial portion of the mediastinum can aid in the diagnosis of mediastinal lymphosarcoma in horses. Such examination should be perfor med in horses with clinical signs of cranial vena cava obstruction in which pleural effusion is detected, or when thoracic lymphosarcoma is suspected.