Neoplastic characteristics of cells are the features that define abnormal, often cancerous, cell growth. Let's analyze each option:
A. A mass of proliferating cells: This is correct. Neoplastic cells typically form a mass due to excessive cell proliferation.
B. Rapid growth of cells: This is also correct. One of the key features of neoplastic cells is their rapid, uncontrolled growth.
C. Invasion and damage to the surrounding tissue: This is correct as well. Neoplastic cells can invade surrounding tissues, which is characteristic of malignancy.
D. Those confined to the original location: This is incorrect. Neoplastic cells that are confined to the original location are called benign, whereas malignant (cancerous) cells invade and spread to other parts of the body.
Thus, the correct answer is A, B, and C only.