Positive reactivity of dysplastic melanocytes with a monoclonal antibody against melanoma melanosomes, MoAb HMSA-2.
A mouse-mouse monoclonal antibody, MoAb HMSA-2, was raised against the melanosomal protein of human malignant melanoma. To characterize the nature of dysplastic melanocytic nevi (DMN), we examined the reactivity of DMN with MoAb HMSA-2 in comparison to that of superficial spreading melanoma (SSM) and common melanocytic nevi (CMN) including junctional melanocytic nevi (JMN) on routine paraffin sections. MoAb HMSA-2 showed several unique immunohistochemical findings: a) MoAb HMSA-2 reacted with melanocytes of DMN in both the epidermis and the dermis, including the pigment granules in the keratinocytes; b) the pigment granules in the keratinocytes of DMN were found to be immature melanosomes transferred from dysplastic melanocytes to keratinocytes; c) the reactivity of epidermal melanocytes in DMN and SSM was stronger than that of junctional component in CMN, though SSM revealed a much stronger reaction than DMN; and d) keratinocytes, especially in a "shoulder" lesion of DMN which was associated with dermal lymphocytic infiltrates, often showed a strong reactivity with MoAb HMSA-2. Thus our study suggested a unique immunohistochemical feature of DMN with deranged melanogenesis as indicated by the reactivity with MoAb HMSA-2.
Maeda
K
K
Department of Dermatology, Sapporo Medical College, Japan.
Maeda
K
K
Jimbow
K
K
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D004416:Dysplastic Nevus Syndrome / Q000276:immunology*; D004817:Epidermis / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008544:Melanocytes / Q000276:immunology* / Q000648:ultrastructure; D008545:Melanoma / Q000276:immunology*; D051379:Mice; D008854:Microscopy, Electron; D009508:Nevus, Pigmented / Q000276:immunology
D000911:Antibodies, Monoclonal