Anaplastic describes tumors with which feature?

• A. Loss of differentiation and loss of cellular orientation; malignant
• B. Increased differentiation
• C. Benign growth
• D. Regenerative hyperplasia

Answer: (A)

Anaplasia describes tumor cells that have lost their specialized features and the organized arrangement of the tissue they arise from. In malignant neoplasms, cells become pleomorphic and hyperchromatic with abnormal mitoses and a loss of polarity, so they no longer resemble the original tissue. This combination—loss of differentiation and loss of cellular orientation—best captures what anaplastic tumors look like and explains their aggressive behavior. Increased differentiation would imply more mature features and is not characteristic of anaplastic, malignant change; benign growths tend to be well-differentiated and organized; regenerative hyperplasia is a reactive, non-neoplastic process.