NQ-118: (C) Kernicterus is the major finding

Diagnosis: Premature infants with hypoxic ischemic changes including periventricular leukomalacia

Pathology of the case: There is no myelin in the cross section. With the overall gyral pattern taken into consideration, this is consistent with an premature infant at about 30 to 32 weeks of gestation.

There is a subtle, tinny opaque dots (arrow). This is grossly suggestive of periventricular leukomalacia (PVL) and this suspicion is confirmed on histologic examination. Minute calcifications are usually present in PVL but they are subtle and can be hard to see. The thalamus being shown here also have patchy discoloration. This is consistent with hypoxic/ischemic insult. If this baby lives, the thalamus is like to develop status marmoratus.

Status marmoratus literally refers to a firm chalky marble-appearing state. Status marmoratus is thought to occur if there is an hypoxic-ischemic insult occurring before the age of 6-9 months at the period of active myelination. It most frequently involves the caudate, putamen and thalamus in 80-90% of cases, and, less often the globus pallidus. Due to the perinatal hypoxic/ischemic insults, there is patchy destruction of the deep gray matter including the thalamus and basal ganglion. When myelin occurs, the landmark for normal myelination is lost. As a result, the final product is gliosis, mineralization of neurons, abnormal myelination pattern, and hypermyelination when myelination occurs. [Click here to see an image of status marmoratus]

There is no kernicterus. Kernicterus appears as bright lemon yellow discolorations. [Click here to see an online image of kernicterus]

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