Immunolocalization of prealbumin as a marker for carcinoid tumours

Abstract

Using a PAP immunoperoxidase technique, we have demonstrated the plasma protein prealbumin in 92 (87 percent) out of a series of 106 carcinoid tumours from various sites. The frequency of detection was greater than with the conventional stains; 83 (78 per cent) of the cases were positive for one or more of these stains. The Grimelius technique was by far the most effective of the conventional stains; it was positive in 81 (76 per cent) cases. We were unable to detect prealbumin in a variety of carcinomas. Although prealbumin identification did not appear to have any advantage over the routine stains in midgut‐derived carcinoids. it was much more effective in the diagnosis of bronchial (foregut) and rectal (hindgut) carcinoids. We believe that prealbumin staining offers a cheap. reliable and valuable method for the detection of carcinoid tumours in routine histopathology.