Cytogenetic studies in primary and metastatic neuroendocrine Merkel cell carcinoma.

Direct preparations of five primary and metastatic neuroendocrine Merkel cell carcinomas of the skin were analyzed using a G-banding technique. A recurrent structural abnormality was a rearranged chromosome #1 with involvement of p and q arms. In two cases this rearrangement appeared as a unique structural cytogenetic change. Evidence for clonal origin and karyotypic stability of this tumor was suggested by the occurrence of the same karyotypic changes in two metachronous metastases and in primary and metastatic tumor specimens of two different patients. The bands involved in rearrangements could be of significance in the molecular process of the neoplastic transformation of Merkel tumor because genes relevant to the differentiation of neural crest-derived tissue have been mapped in those regions.