What histological feature is indicative of chronic inflammation?

Chronic inflammation is characterized by a progressive and sustained response that lasts for an extended period, typically longer than several weeks. In this context, the presence of lymphocytes and plasma cells is particularly indicative of chronic inflammation.

Lymphocytes are immune cells that play a critical role in the adaptive immune response. They are predominantly found in chronic inflammatory lesions, often indicating a prolonged activation of the immune system. Plasma cells, which are differentiated B lymphocytes, produce antibodies and are often present during ongoing immune responses, particularly in sites of chronic infection or inflammation. The combination of these cells signifies a more complex and regulated immune response to persistent stimuli, such as pathogens or tissue injury.

In contrast, the presence of neutrophils is commonly associated with acute inflammation, where rapid immune responses to infections or injury are paramount. Fibrous tissue, while often seen in chronic states due to tissue repair processes, is not specific to inflammation itself, and its presence can overlap with various conditions. Eosinophils are more typically associated with allergic reactions and parasitic infections rather than chronic inflammation, making them less characteristic in this context.

Therefore, the presence of lymphocytes and plasma cells distinctly marks chronic inflammation and highlights the type of immune response involved in this pathological state.