Acral lentiginous melanoma: an immunohistochemical study of 20 cases.
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.
Kim
You Chan
YC
Department of Dermatology and Pathology, Dankook University, College of Medicine, Cheonan, Chungcheong Nam Do, Korea. kyccc@dku.edu
Lee
Min Geol
MG
Choe
Sung Whan
SW
Lee
Min Cheol
MC
Chung
Han Gil
HG
Cho
Sang-Ho
SH
D000368:Aged; D000951:Antigens, Neoplasm / Q000032:analysis; D015415:Biomarkers; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007633:Keratins / Q000032:analysis; D058965:MART-1 Antigen; D008297:Male; D008545:Melanoma / Q000276:immunology / Q000473:pathology*; D058950:Melanoma-Specific Antigens; D018396:Mucin-1 / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis*; D009418:S100 Proteins / Q000032:analysis*; D012878:Skin Neoplasms / Q000276:immunology / Q000473:pathology*
D000951:Antigens, Neoplasm; D015415:Biomarkers; D014408:Biomarkers, Tumor; C400901:CAM 5.2 antigen; D058965:MART-1 Antigen; C548667:MLANA protein, human; D058950:Melanoma-Specific Antigens; D018396:Mucin-1; D009363:Neoplasm Proteins; D009418:S100 Proteins; D007633:Keratins