A 58-year-old woman undergoes lumpectomy for breast cancer. One month following surgery, she notices a firm 0.3-cm nodule along one edge of the surgical incision. Biopsy of this nodule reveals chronic inflammatory cells, multinucleated giant cells, and extensive fibrosis. The multinucleated cells in this nodule most likely formed in response to which of the following pathogenic stimuli?

Granulomatous inflammation is a subtype of chronic inflammation, which develops when acute inflammatory cells are unable to digest the injurious agent (e.g., suture or talc). Fusion of macrophages within the lesion results in the formation of multinucleated giant cells. None of the other choices elicit this type of granulomatous reaction Diagnosis: Granulomatous inflammation (foreign body granuloma)