What is the definition of a tumor?

A tumor is defined as a new growth of abnormal cells. This definition is fundamental in understanding the nature of tumors, which can arise in various tissues of the body. Tumors can be classified as benign or malignant, with benign tumors being non-cancerous and generally not invasive, while malignant tumors are cancerous and have the potential to spread to other parts of the body.

The concept of abnormal cell growth is crucial because it indicates a disruption in the normal regulatory processes of cell division and differentiation. Factors such as genetic mutations and environmental influences can contribute to this dysregulation, leading to the formation of tumors.

Understanding tumors as abnormal growths provides a basis for diagnosing various conditions and determining appropriate treatments. In contrast, the other options relate to different medical phenomena. Infections involve pathogens, inflammation is a response to injury or infection, and benign skin conditions do not encapsulate the broader definition of tumor growth. Recognizing these distinctions is key in medical practice and education.