An unusual dysplasia-malformation-cancer syndrome in two patients

We report two patients with a similar syndrome of gross malformation of a lower limb and contiguous structures due to involvement with dysplastic, teratomatous tissue. This dysplasia seems to have arisen in a paramedian position in the embryonic hindquarter at the time of lower limb-bud differentiation. Malignant degeneration at 5--7 months led to metastases and death in both cases around 1 year of age. The behavior of the dysplastic/oncoplastic tissue suggests a 2-"mutational" causal model. This is an apparently previously undescribed formal genesis syndrome.