This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Histopathological findings, Subject name: Dental
Irregular acanthosis is seen in : 
Select and explain. 
A. Chronic eczema, B. Lichen planus, C. Psoriasis, D. Acute eczema
B: Lichen planus
Answer: B: Lichen planus 
Explanation: Acanthosis - increase in number of cells in the Malpighian or prickle cell layer of the epidermis Increased thickness of the epidermis may result from an increased length of rete ridges or may affect the whole epidermis Acanthosis is commonly accompanied by other histological changes - as hypergranulosis, hyperkeratosis and papillomatosis.May be seen in a wide variety of inflammatory and neoplastic disorders. Irregular acanthosis - Lichen planus(saw tooth acanthosis) Regular acanthosis - Chronic eczema , psoriasis