Squame

EGF increased proliferation and squame formation and induced keratinization in cultured MA cells, an observation heretofore not reported in rat MA cells.

They flatten further and become compacted into a dense keratinous layer known as the stratum corneum. The superficial flake-like squames are eventually cast off (desquamate).

Squames begin life as normal cells in the lower layers of the epidermis but, as they travel towards the surface, they progressively lose all recognizable contents, becoming plates of mainly keratin protein, based on a progressive deposition of protein on the intermediate filaments of the cytoskeleton.

Here the invading cell masses of the cancer consist of short thick squames, and the nearest approach to cell nest formation may be only a whorling of those squames in the centres of the cell masses.

Second, if it is a squame, the nuclear size and chromatin pattern are determined. If the nucleus of this squame is plump and vesicular with an intact chromatin pattern, the cell is an intermediate; if it is pyknotic, shrunken, and hyperchromatic and lacks chromatin pattern, the cell is a superficial.

As the cells divide and the vaginal lining thickens, the cells nearest the lumen become nonviable and lose the characteristic appearance of a healthy cell monolayer. The misshapen, clumped cells are termed cornified. Specific cell types are superficial cells and anuclear squame cells (Fig. 2-2).

Most of the right temporal bone is well-preserved, with the exception of much of the zygoma and the upper edge of the temporal squame (Plate 8).

A tapering of the fragment on its inner surface, and the pattern of branching of the middle meningeal vessel grooves, have enabled us to identify the piece as most probably part of the left temporal squame of a cranium.