In veterinary oncology, which of the following is a hallmark of malignancy?

In veterinary oncology, the hallmark of malignancy is characterized by a distinctive feature: metastasis to distant sites. This process involves the spread of cancer cells from the primary tumor to other areas of the body, establishing secondary growths that can affect various organs and tissues. Metastasis is a fundamental characteristic of malignant tumors and distinguishes them from benign tumors, which typically remain localized and do not invade surrounding tissues or spread.

Well-defined edges of tumors typically suggest a benign nature, as malignant tumors often present with irregular, infiltrative borders due to their aggressive growth patterns. Similarly, a slow growth rate is more commonly associated with benign tumors, which tend to be less threatening and grow at a more controlled pace. Encapsulation refers to the formation of a fibrous capsule around the tumor, a feature often seen in benign tumors that helps to contain their growth, while malignant tumors frequently lack such a defining boundary.

Thus, the ability of malignant tumors to metastasize is crucial to understanding their behavior, prognosis, and treatment strategies in veterinary oncology.