March 11, 2014

Slide Review: Thick skin and sun damaged skin

Thick and/or sun damaged skin will appear as a translucent layer of cells outside the epidermis. This section shows scabby, sun damaged tissue, so the layer of cells is rough and uneven. In the mid dermis, the grayish/lavender area is most likely actinic elastosis, or the accumulation of abnormal elastic tissue in the dermis, also a result of sun damage.
This next section shows the thick skin found in the palms of the hand or the soles of the feet. Note that even though the image (courtesy of http://www.dartmouth.edu) points out the "thickened layer of squamous cells," it is not referring to SCC. Healthy squamous cells are a normal part of the superficial epidermis. The outermost squamous cells are heavily keratinized, creating a thick layer of dead cells that protects our hands and feet. 
For comparison, here is a section of normal tissue only a thin layer of dead squamous epithelial cells.