Microinvasive lentigo maligna melanoma.
Ninety-one skin biopsy specimens previously identified as lentigo maligna were examined for the presence of microinvasion, using the demonstration of S100 protein within atypical cells as the means for locating these superficial foci. In 14 cases, atypical melanocytes were identified, most often in the papillary dermis. The mean depth of invasion in this group was 0.23 mm with a range of 0.10 mm to 0.75 mm. In these cases, atypical cells were difficult if not impossible to identify in routinely processed sections, either because the invasive cell was a spindle cell variant and indistinguishable from a fibrohistiocytic cell, because the invasive cells were occasionally solitary or in small groups, or because there was an inflammatory infiltrate that obscured the tumor cells. Recent studies of lentigo maligna melanoma have revealed no better prognosis when compared to that of other forms of malignant melanoma after normalization for depth and body location. We therefore advocate close examination of lentigo maligna with the use of appropriate immunohistochemical techniques if there are areas of dermal fibrosis or inflammation that might obscure invasion.
Penneys
N S
NS
Department of Dermatology, University of Miami School of Medicine, FL.
D000368:Aged; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008544:Melanocytes / Q000032:analysis / Q000473:pathology; D008545:Melanoma / Q000032:analysis / Q000473:pathology*; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D009418:S100 Proteins / Q000032:analysis; D012878:Skin Neoplasms / Q000032:analysis / Q000473:pathology*
D009418:S100 Proteins