Which pathologic processes is an example of dysplasia | Crack AIIMS, NEET 2017 with NIME MCQs

Which of the following pathologic processes is an example of dysplasia? 

A. Actinic keratosis 
B. Chronic cystitis 
C. Chronic bronchitis 
D. Ulcerative colitis

Ans. A.  

Actinic keratosis is a form of dysplasia in sun-exposed skin. Histologically, such lesions are composed of atypical squamous cells, which vary in size and shape. They show no signs of regular maturation as the cells move from the basal layer of the epidermis to its surface. Dysplastic epidermis shares many features with squamous cell carcinoma, and untreated actinic keratosis often gives rise to invasive cancer. Chronic cystitis and bronchitis may result in foci of metaplasia, but these tend to be composed of differentiated cells that show no nuclear atypia. Squamous metaplasia of the columnar epithelium of the bronchi or the transitional epithelium of the urinary bladder may become dysplastic, but this transition is unpredictable. Therefore, these metaplastic lesions should not be grouped together with actinic keratosis, which is often referred to as “squamous cell carcinoma, one half.” Although dysplasia and even neoplasia can occur in the colonic mucosa affected by ulcerative colitis or in the columnar epithelium of Barrett’s esophagus, by itself neither ulcerative colitis nor Barrett’s esophagus should be classified as dysplasia.