Benign nodular hyperplasia - Figure 7. Cytological features - intranuclear inclusions.

The correct interpretation of intranuclear holes is essential to a correct cytological differential diagnostics. Intranulear holes may be drying artifacts (images in the first row), projections of extranuclear vacuoles (images in the second row) or invagination of nuclear membrane. The latter is the most important sign of papillary cancer but may be observed even in benign lesions (third row of images) and is characterized by sharp, regular border.