Figure 55.

Epithelial membrane antigen (EMA) expression in normal (a,c) and neoplastic (b,d) perineurial cells (top panels: (a,b)) and plasma cells (bottom panels: (c,d)). It should be noted that EMA is positive in certain non-epithelial cells and their tumors (perineurioma and multiple myeloma). Perineurial cells surrounding the peripheral nerve sheath represent peripheral meningothelial cells. Chronic cervicitis containing numerous plasma cells is covered with EMA-positive columnar epithelial cells.