Chronic bronchitis can be a premalignant condition, which involves:: (A) Columnar to squamous, (B) Squamous to columnar, (C) Squamous to cuboidal, (D) Cuboidal to squamous
Answer is A. Ans. (a) Columnar to squamous(Ref: Robbins 9th/pg 679)Chronic bronchitis is an example of squamous metaplasia in which normal columnar epithelium of respiratory tract is replaced by squamous epithelium;