NQ-058
Answer:
(B) Olfactory bulb and tract
Pathology of this case:
The cortical
gray matter ribbon seems to be exceptionally thin in some area and appears
like a chalky thin line (black arrow). These are features of laminar necrosis
of the cortical gray matter in global ischemia. In fact, this is resolved
infarction and the chalky appearance is resulted from the mineralization
(calcification) of the necrotic cortex. These changes are particularly
prominent in the area identified by the black arrows. These are the
so-called borderline zone between the anterior and middle cerebral artery.
These areas are most prone to hypoxic/ischemic changes due to fact that it
is located at the far edge of both the anterior and middle cerebral artery
territories. Laminar necrosis
There are
other areas with necrosis and collapse in putamen and thalamus (white
arrow).
In essence, this is most consistent with a survivor of a hypoxic/ischemic insult because grossly the lesions are in the resolving or resolved phase of an infarction. It should be noted that patients surviving systemic hypotension and cardiorespiratory arrest with successful resuscitation often have necrosis of basal ganglia.
Ng, HK.
Hypotensive symmetrical hemorrhagic necrosis of the basal ganglia and brain
stem. Pathology. 1994 Jan;26(1):23-7.
Acute infarction due to obstruction of a major cerebral artery such as anterior
or middle artery
usually leads to necrosis that follows the vascular territory. In the current
case, the lesions are rather symmetrical and this is a strong sign for global
ischemic/hypoxic changes.
The cortical ribbon is prominent and dusky which makes the white matter looks
prominent. But the white matter is normal in this case. In
leukodystrophy, the white matter
would lose its opaque white appearance and appears more translucent due to loss
of myelin.
The findings in the cortical ribbon should not be mistaken as those from
meningitis. There is no swelling or
pus or other features to suggest a gross diagnosis of meningitis in this case.