This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
A 50 years old man has a 2 year history of facial bullae & oral ulcers. Microscopic smear from skin lesions is most likely to disclose – a) Tzanck cellsb) Acantholytic cellsc) Necrosisd) Koilocytosis 
Select and explain. 
A. c, B. d, C. ab, D. ac
C: ab
Answer: C: ab 
Explanation: Facial bulla and oral ulcers (mucosal involvement) in a 50 years man suggest the diagnosis ofpemphigus vulgaris. The smear from the lesions will show ancantholytic cells also referred to as Tzank cells, which are separated keratinocytes.