Figure 4

Representative ectopic lymph node-like structures in melanoma examined by immunohistochemistry.

CD20⁺ B cells are concentrated as a follicle, with CD3⁺, CD4⁺ and CD8⁺ T cells appearing in the parafollicular cortex or marginal zones and with some dispersion into the follicle. CD86⁺ antigen presenting cells appear to be dispersed throughout the ectopic lymph node-like structure whereas Fox P3⁺ staining cells are few in numbers (a.,b.,c.). A melanoma metastasis displaying numerous CD20⁺ B cell, CD3⁺ T cell-containing, ectopic lymph node-like structures is also shown (d.). Magnification: x200.