What term describes the unlimited division of malignant tumor cells?

The term that describes the unlimited division of malignant tumor cells is cell immortality. This phenomenon occurs when cancer cells are able to bypass the normal cellular mechanisms that limit cell division and growth. Typically, normal cells have a finite number of divisions (known as the Hayflick limit) due to factors like telomere shortening. However, malignant cells can maintain their telomeres through various means, such as activating the enzyme telomerase, allowing them to replicate indefinitely. This characteristic is a defining feature of cancer and contributes to the aggressive nature of tumors, as these cells continue to divide and grow uncontrollably, leading to tumor progression and metastasis.

In contrast, other options refer to different cellular processes. Contact inhibition relates to the tendency of normal cells to stop dividing when they come into contact with one another. Malignant growth describes the general concept of tumor formation but does not specifically address the unlimited nature of cell division. Apoptotic resistance refers to the ability of cancer cells to evade programmed cell death, which is different from the aspect of unlimited division.