Acral lentiginous melanoma: an immunohistochemical study of 20 cases

Int J Dermatol. 2003 Feb;42(2):123-9. doi: 10.1046/j.1365-4362.2003.01583.x.


Background: Though acral lentiginous melanoma (ALM) is a major type of malignant melanoma, no immunohistochemical study on this type of melanoma has been reported.

Objective: The purpose of this study is to analysis the immunohistochemical findings of ALM using routinely used immune markers.

Methods: An immunohistochemical study was performed on paraffin sections of 20 ALMs using S-100 protein, HMB-45, MART-1, vimentin, epithelial membrane antigen (EMA) and CAM 5.2.

Results: S-100 protein (95%) was found to be a more sensitive marker than either HMB-45 (80%) or MART-1 (70%) for recognizing ALM. Melanin bleaching was useful for recognizing heavily pigmented ALM using both S-100 protein and HMB-45. The intensity of HMB-45 correlated well with the melanin content. However, there was no significant correlation between the intensity of S-100 protein and the melanin content. One and two out of 20 cases stained focally with EMA and CAM5.2, respectively, but these cases stained also with HMB-45 and/or S-100 protein.

Conclusions: S-100 protein and HMB-45 were relatively sensitive markers for recognizing ALM. Despite the occasional positivity for the epithelial markers in ALM, all epithelial marker-positive cases stained also with HMB-45 and/or S-100 protein. Therefore, we recommend that the panel of antibodies used for recognizing ALM should contain at least S-100 protein and HMB-45.

MeSH terms

  • Aged
  • Antigens, Neoplasm / analysis
  • Biomarkers
  • Biomarkers, Tumor / analysis*
  • Female
  • Humans
  • Immunohistochemistry
  • Keratins / analysis
  • MART-1 Antigen
  • Male
  • Melanoma / immunology
  • Melanoma / pathology*
  • Melanoma-Specific Antigens
  • Mucin-1 / analysis
  • Neoplasm Proteins / analysis*
  • S100 Proteins / analysis*
  • Skin Neoplasms / immunology
  • Skin Neoplasms / pathology*


  • Antigens, Neoplasm
  • Biomarkers
  • Biomarkers, Tumor
  • CAM 5.2 antigen
  • MART-1 Antigen
  • MLANA protein, human
  • Melanoma-Specific Antigens
  • Mucin-1
  • Neoplasm Proteins
  • S100 Proteins
  • Keratins