Primary neuroendocrine carcinoma and small-cell malignant lymphoma of the skin. A discriminant immunohistochemical comparison.
In selected instances, primary cutaneous neuroendocrine carcinoma (PCNEC) and small-cell malignant lymphoma (SCML) of the skin may display similar clinical presentations and microscopic appearances, leading to diagnostic uncertainty. We applied monoclonal antibodies to epithelial membrane antigen (EMA), Ia antigen, and leukocyte common antigen (LCA) to 31 cases of PCNEC and 12 of small-cell lymphoma cutis, using a combined PAP and ABC procedure, to determine whether or not such stains were capable of separating the two neoplasms. All cases of SCML were reactive for LCA, while this determinants was not seen in any example of PCNEC. Anti-Ia antigen labelled 11 of 12 cases of SCML, and also failed to stain neuroendocrine carcinomas. Lastly, EMA was observed in 25 of 31 cases of PCNEC, but it was found in one lymphoplasmacytoid lymphoma as well. Bayes' univariate statistical analysis of these data indicates that anti-LCA, anti-EMA, and anti-Ia antigen are capable of discriminating between the tumors in question, with anti-LCA being the most effective.
D000230:Adenocarcinoma / Q000175:diagnosis / Q000473:pathology*; D000911:Antibodies, Monoclonal; D003937:Diagnosis, Differential; D006649:Histocompatibility Antigens / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D017493:Leukocyte Common Antigens; D008223:Lymphoma / Q000175:diagnosis / Q000473:pathology*; D008565:Membrane Proteins / Q000276:immunology; D018396:Mucin-1; D012878:Skin Neoplasms / Q000175:diagnosis / Q000473:pathology*
D000911:Antibodies, Monoclonal; D006649:Histocompatibility Antigens; D000949:Histocompatibility Antigens Class II; D008565:Membrane Proteins; D018396:Mucin-1; D017493:Leukocyte Common Antigens