A case of pleuropulmonary blastoma (childhood variant of pulmonary blastoma) was examined using histological, immunohistochemical, ultrastructural and cytogenetic methods. The tumour consisted of undifferentiated 'blastematous' areas admixed with zones of rhabdomyoblastic and chondroid differentiation and fascicular areas. Desmin and S-100 protein immunoreactivity confirmed the myogenic and cartilaginous differentiation. Ultrastructurally only undifferentiated mesenchymal cells were present. The cytogenetic analysis revealed abnormalities of 2q. Involvement of 2q has also been described in hepatoblastoma and embryonal rhabdomyosarcoma. Although further confirmation is needed, our cytogenetic findings in pleuropulmonary blastoma suggest common genetic mechanisms in some paediatric embryonal malignancies.