The specimen consists of two slices of brain. In the lower section a focus of metastatic tumour is
seen in the left superior parietal gyrus. There is expansion of the white matter in the left parietal
lobe with obliteration of the gyral pattern both laterally and superiorly. Microscopic examination
of the tumour showed it to be metastatic poorly differentiated adenocarcinoma that had evoked
profound gliosis and oedema in the adjacent white matter. The primary site of the tumour was
not discovered at post mortem. The upper slice shows a congenital abnormality of the septum
pellucidum known as bulbi septae pellucidi this appears to develop from splitting of the septum
pellucidum during organogenesis.