S11C24P19-3: Many of the nuclei in this field contain intra-nuclear inclusions (blue arrows). Each intra-nuclear inclusion is homogeneous and pale pink; it partially, or completely, fills the nucleus. Chromatin is compressed at the nuclear membrane. Some of the cells are less affected; they contain deeply basophilic keratohyaline granules (green arrow points to an example). In this field, the cytoplasmic inclusions clearly can be distinguished from the keratohyaline granules; they even differ tinctorially.

S11C24P19-4: This is a papilloma virus infection, but the patterns are more subtle than those of S11C24P19-1. The changes in the superficial unit of the epidermis are of a type that qualifies as a koilocytotosis. The epidermis shows basal and superficial unit hyperplasia. In addition, there is mild papillomatosis with a prominent granular layer. Many of the keratinocytes of the superficial unit of the epidermis have enlarged nuclei and prominent perinuclear clear haloes. This combination of nuclear changes and perinuclear cytoplasmic vacuolization qualifies as koilocytosis (verruca plana, or flat wart).

S11C24P19-5: At higher magnification, the koilocytotic features are well-developed (verruca plana). A relatively normal keratin layer is a common feature of this variant of papilloma virus infection, but some examples will show parakeratosis and slight papillomatosis. The distinctions between verruca vulgaris and verruca plana often are arbitrary.

S11C24P19-6: Condyloma acuminatum is a variant of papilloma virus infection with a predilection for the ano-genital areas. In this example, the koilocytotic changes are well developed; the epidermis shows hyperplasia of both the superficial and basal units. Keratohyaline granules are not a prominent feature and parakeratosis is prominent at the surface. Lesions of this type show variable degrees of inflammation; this example shows only mild infiltrates .

S11C24P19-7: In this example of condyloma acuminatum, the koilocytotic changes are prominent with well-developed perinuclear haloes. Nuclei vary in size  and some show marginated chromatin. Focally to the left and above, some of the cells contain keratohyaline granules that vary in size and are loosely spaced.