Within the 3rd ventricle is a well-circumscribed enhancing mass which measures 22 x 31 x 22 mm. It is associated with oedema in the thalamus bilaterally, and seems to impede the outflow of the ventricles to some degree, as are temporal horns are slightly prominent, but without significant hydrocephalus. It is an isolated abnormality, with no other enhancing lesions seen elsewhere within the brain.
Conclusion: Third ventricular mass, in a patient with a large pulmonary mass and mediastinal nodes almost certainly represents a metastasis, presumably from a lung primary.