Surgical specimens of 72 adrenocortical tumours (ACTs) were investigated. Histologically, 57 tumours were classified as adenomas and 15 as carcinomas. In 9 of the latter cases, distant metastases and/or lethal outcome of disease was recorded. Immunocyto-chemistry showed only 2 ACTs to be positive for cytokeratin and 6 for vimentin. None of the 72 tumours showed argyrophilia or immunoreactivity for epithelial membrane antigen (EMA), S-100 protein, chromogranin A, Leu 7 or Leu-M1, while 31 cases exhibited positivity on immunostaining with a polyclonal antiserum against synaptophysin. All 72 ACTs were immunoreactive with the recently described antibody D11. Thus the panel of antibodies described here could not discriminate between adenomas and carcinomas or between carcinomas with aggressive and indolent behaviour. Immunostaining with D11 and for EMA and Leu-M1 may help to distinguish ACTs from phenotypically similar lesions of different histogenesis.
