The hematoxylin-eosin–stained sections revealed an inflammatory infiltrate that was composed of lymphocytes, histiocytes, and foreign body giant cells located near cavities of different sizes (Figures 3 and 4). The empty spaces produced a “Swiss cheese” appearance in the deep dermis and in the subcutaneous fat. Immunocytochemical studies using CD3 and CD20 antisera demonstrated a paucity of T and B lymphocytes, with a higher number of T cells. CD68 antiserum demonstrated several hundred histiocytes. This histologic picture, along with a clinical history of injections, is consistent with a foreign body reaction.
Pathology Quiz Case 1—Diagnosis. Arch Otolaryngol Head Neck Surg. 2007;133(10):1064. doi:10.1001/archotol.133.10.1064