Which characteristic is common to both benign and malignant tumors?

Benign and malignant tumors share the characteristic of being classified as tumors, which are abnormal growths or masses of cells that can result from uncontrolled cell division. Tumors arise from various types of cells and exhibit differences in their behavior and effects on the body, but the fundamental defining feature is their classification as tumors due to this abnormal proliferation.

Benign tumors typically remain localized and do not invade surrounding tissues or spread to other parts of the body, while malignant tumors can invade adjacent tissues and are capable of metastasis, which means they can spread to distant sites. Not all tumors require surgery; for instance, some benign tumors may not cause significant issues and can be monitored without intervention. Though both types can lead to cell damage indirectly due to pressure effects or secretions, this is not a defining characteristic that applies universally to both types. Metastasis is exclusively a feature of malignant tumors, making that option incorrect for both types.

Overall, the classification of both benign and malignant growths as tumors is the most inclusive and unifying characteristic.