Soft tissue mass, preauricular. A, Dense lymphoid and eosinophilic infiltrates are seen in the soft tissues; note peripheral nerve lower portion (hematoxylin-eosin, × 40). B, The lymphoid infiltrate rich in eosinophils surrounds numerous thin-walled vessels (hematoxylin-eosin, × 100). C, The thin-walled vessels contain plump endothelial cells resembling the high endothelial or postcapillary venules of lymph nodes. Numerous eosinophils are also present (hematoxylin-eosin, × 40).
Lymph node, adjacent to preauricular soft tissue mass. A, Prominent reactive-appearing germinal centers are seen within this hyperplastic lymph node. Foci of dense eosinophilic infiltrates forming eosinophilic microabscesses, impinge directly into germinal centers (hematoxylin-eosin, × 40). B, Reactive germinal center with abundant nuclear debris, numerous Warthin-Finkeldey-type polykaryocytes, and delicate eosinophilic matrix (hematoxylin-eosin, × 100).