Which term describes a tumor that does not invade or metastasize?

• A. Malignant.
• B. Carcinoma in situ.
• C. Metastatic.
• D. Benign.

Answer: (D)

Understanding how tumors behave is the key idea here: some stay localized and do not invade or spread, and that describes a benign tumor. Benign tumors grow slowly, are typically well circumscribed and encapsulated, and they do not invade surrounding tissues or metastasize to distant sites. This localized, noninvasive nature is what makes them less dangerous in terms of spread, even though they can still cause problems if they press on nearby structures or disrupt normal function.

In contrast, malignant tumors invade neighboring tissues and are capable of metastasizing to distant organs, which is what makes them more dangerous. Carcinoma in situ refers to a noninvasive lesion confined to the original epithelial layer and not yet breached the basement membrane; it’s noninvasive but represents a pre-malignant state. Since the question specifies a tumor that does not invade or metastasize, the term that fits best is benign.