NCIt definition : A dome-shaped, rapidly growing neoplasm composed of well differentiated squamous cells.
It almost always affects the skin and usually occurs on sun-exposed areas of the body,
most often the head, neck, and limbs. Rare cases have been reported in extracutaneous
sites including the conjunctiva, subungual space, and vulva. It is considered a variant
of well-differentiated squamous cell carcinoma with distinct clinical behavior.;