Which condition involves change in the usual structure of a tissue or organ?

The correct answer is an anomaly, which refers to a deviation or departure from the normal structure or function of a tissue or organ. Anomalies can manifest as structural changes that may be congenital or acquired, leading to conditions where the usual arrangement and composition of tissues are altered. This alignment with the definition makes it clear that an anomaly signifies a specific and identifiable change in organ or tissue structure.

In contrast, other terms have different meanings. Infection typically implies the invasion of pathogens causing illness, rather than a structural alteration. Hypertrophy refers to the increase in the size of cells or tissue due to a stimulus, without necessarily changing the overall structure. Inflammation denotes a response to injury or infection characterized by swelling, redness, and heat, which can be associated with changes in tissue but is more about the body's response than a structural change in terms of organization. Thus, an anomaly specifically highlights the actionable change in structure.