In an attempt, to overcome the lack of preclinical models for adrenocortical carcinoma (ACC), we recently aimed at the development of patient-individual tumor models for ACC. During these studies one xenograft (MUC-1), derived from a neck metastasis of an ACC, showed extraordinary engraftment properties and sustained tumor growth over several passages in the murine host. During ongoing studies we investigated and compared all currently available xenograft models for ACC (NCI-H295R, SW-13 and SJ-ACC3) regarding Ki67, SF-1 and EGF-receptor status among others with the newly established MUC-1 xenografts. In vitro, we established a primary culture based on explanted MUC-1 xenograft pieces. A first try of cell culture establishment failed after several passages due to a massive contamination by murine fibroblasts. Thus, we initiated a second round of culturing involving continuous and highly specific murine and human fibroblast removal. The resulting multi-clonal cell suspension is now viable in passage 15. In these cultures, cross-contamination by murine fibroblasts could be excluded on the basis of a Universal-Primer Probe-Assay. Representative pictures of passages 4, 7, 10 and 13 demonstrate furthermore specific Ki67 as well as nuclear SF-1 and cytoplasmic 3ßHSD immunopositivity. Moreover, genetic characteristics of MUC-1 cells were investigated by PCR-Single-Locus Technology ensuring a distinct marker profile different from that of NCI-H295R and SW-13 cells. Thereby, MUC-1 cells were recently authentified as a novel adrenocortical cell line of human origin.