What is acanthosis

acanthosis n. an increase in the number of 'prickle cells in the innermost layer of the epidermis, leading to thickening of the 
epidermis. Acanthosis nigricans is associated with "insulin resistance; it is characterized by papillomatous growths, mainly in the armpits, giving the skin a pigmented ap¬pearance and a velvety texture. It may be benign or malignant. Pseudoacanthosis ni¬gricans is more common and is associated with obesity.