The event was funded by the National Institutes of Health, a federal agency dedicated to medical research. However, evidence now suggests that radiographic brain imaging and histologic studies are unable to distinguish these tubers from isolated cortical dysplasia.
Histology is the science of the minute structure of cells, tissues and organs.
In particular, the two subependymal lesions have a histologic and radiographic appearance that differs from the cortical tuber, whereas the giant cell astrocytoma is the only one that tends to enlarge. Hypomelanotic macules are considered a new grouping, whereas the histologically similar forehead plaque, facial angiofibroma, and renal and retinal hamartomas, continue to be considered major features used in diagnosis. As we learn more about TS and as diagnostic genetic testing becomes more widely available, the diagnostic criteria will again be revised.