A heterogeneous mass was identified in the left hemithorax. There was a small amount of aerated lung identified in the caudodorsal left hemithorax. There were multiple cavitary like regions identified within this mass which was immediately adjacent to the heart and the cranial mediastinal vasculature.
Rule outs for the pulmonary mass involving the left cranial lung lobes should include granuloma, neoplasia, with lesser consideration given to hematoma and torsed lung lobe.
There was a large greater than 6 cm in diameter heterogeneous soft tissue attenuation mass identified in the left ventral thoracic cavity. The mass began caudally just cranial to the diaphragm and extended cranially to the level of the first intercostal space on the right side. The mass crossed midline to the right side and resulted in dorsal deviation of the trachea, dorsal and rightward deviation of the cardiac silhouette, and dorsal deviation of the left cranial mainstem bronchus. The mass demonstrated diffuse heterogeneous mild contrast enhancement. The mass was adjacent to but did not surround the arterial and venous structures in the cranial mediastinum. The mass was compressing the majority of the left cranial lung lobe dorsally.
Organs of origin for the left thoracic mass would include mediastinal, specifically thymus and left cranial lung lobe. Primary differentials for mass would include neoplasia and granuloma. Hematoma would be considered less likely. The mass was adjacent to but not surrounding the vasculature within the cranial mediastinum and the heart.
Ultrasound-guided fine needle aspirate of thoracic mass – cell population was suggestive of a thymoma. Other differentials include thymic lymphoma or pulmonary lymphoma.
Thoracotomy was performed and a large mediastinal mass was removed.
Histopathology of mass – thymoma.
Chemotherapy and radiation therapy were offered as treatment options.