Canine histiocytic sarcoma presenting as a target lesion on brain magnetic resonance imaging and as a solitary pulmonary mass.

A 6-year-old spayed female miniature schnauzer presented with generalized seizures and progressive multifocal intracranial neurologic disease. Thoracic radiographs and computed tomography (CT) revealed a large solitary pulmonary mass within the right cranial lung lobe. On brain magnetic resonance imaging (MRI), a solitary intraparenchymal mass within the left piriform lobe had a "target" appearance on both pre- and postcontrast sequences.