Figure 1

Hematoxylin and eosin-stained groin and cervical lymph nodes. A and B, architecture of the groin and cervical lymph nodes, respectively (×40). C and D, sinus expansion and histiocytes in the groin and cervical lymph nodes, respectively (×100). E, a macrophage engulfing a blood cell (×400). F, many macrophages engulfing many blood cells (×400). G, about six plasma cells in the medullary cord of the groin lymph node (×200). H, more than 20 plasma cells in the medullary cord of the cervical lymph node (×200).