Metastasizing vulvar carcinosarcoma with squamous carcinomatous and leiomyosarcomatous differentiation: genetic evidence of clonal origin

In this report, we present the first case of a vulvar carcinosarcoma with squamous carcinomatous and leiomyosarcomatous differentiation. Comparative genomic hybridization was used to analyze clonality of the two tumor components. A widely identical pattern of genetic imbalances in the comparative genomic hybridization analysis in both the carcinomatous and the sarcomatous tumor component strongly supported the concept of a bidirectionally differentiated neoplasm. In both tumor components and two lymph node metastases, an amplicon was detected on chromosome 11q12-q13, homing the cyclin D1 gene locus. In contrast, exclusively in the sarcomatoid component, a characteristic amplicon on 12q13-q14 was found. The cytogenetic profile of the lymph node metastases revealed an increase in imbalances compared with the primary tumor. In summary, we found strong indications for a clonal origin of the two tumor components in a vulvar carcinosarcoma and a good correlation of the histological morphology with the pattern of genetic imbalances.