Dysplasia — Abnormal Precancerous Cell Growth

Under microscopic examination, dysplasia is characterised by an alteration in cell size, shape, and architectural organisation within an epithelium. Pathologists evaluate specific morphological features, including cellular pleomorphism, increased nuclear-to-cytoplasmic ratio, hyperchromasia, and an increased rate of atypical mitotic figures.

Dysplasia is generally graded on a spectrum as mild, moderate, or severe (or low-grade versus high-grade). Unlike malignant invasive neoplasms, dysplastic cells do not breach the basement membrane or invade underlying stroma. While mild dysplasia may regress spontaneously when the inciting cause resolves, severe dysplasia carries a substantial probability of advancing to carcinoma in situ or invasive malignancy if left unaddressed.

Finding dysplasia provides a valuable window of opportunity for cancer prevention. Because it often causes no symptoms, it is typically caught during routine screening tests like cervical smears or colonoscopies. Understanding the grade of dysplasia helps patients and clinicians decide whether a watchful-waiting approach with surveillance is appropriate, or if a minor procedure to excise or ablate the affected tissue is necessary. Addressing high-grade dysplasia early effectively eliminates the risk of those specific cells progressing to an invasive, life-threatening tumour.

Dysplasia is diagnosed through histopathological or cytological analysis. Common procedures include cervical cytology (Pap tests), colposcopic biopsies, colonoscopic polyp biopsies, and endoscopic mucosal biopsies. Testing for high-risk human papillomavirus (HPV) or Helicobacter pylori may be performed alongside biopsy analysis to determine underlying causes.

Dysplasia can occur in various epithelial tissues throughout the body. It is most commonly identified in the cervix (cervical intraepithelial neoplasia), colon and rectum (dysplastic polyps), oesophagus (Barrett's oesophagus with dysplasia), oral cavity, stomach, and skin (actinic keratosis).

Management corresponds to the grade of dysplasia and organ involved. Mild dysplasia often requires only close surveillance to see if it resolves. High-grade dysplasia typically warrants local intervention, such as loop electrosurgical excision procedure (LEEP) for the cervix, endoscopic mucosal resection (EMR) for gastrointestinal lesions, or cryotherapy, avoiding the need for extensive cancer surgeries.