Development of a liposarcoma out of the capsules of a hygroma

We treated a patient who had a very rare finding: the development of a malignoma out of the capsules of the subdural hygroma covering the right occipitotemporal brain. Lumbar encephalography and arteriography confirmed the fact that surgery was necessary. A subdural-auricular shunt was performed and revised 2 years later. During the second operation, the external and internal capsules were removed in addition to the shunt. 3 years later the hygroma and large capsules were removed again and a ventricular-subdural drainage performed. 1 year later once more a subdural-auricular shunt was performed. 10 months later a tumour was found to be a pseudomucinous liposarcoma with large hyperchromatic nuclei and oval cells with large vacuoles of neutral fat. Renewed growth of the tumour led to the child's death. The histological and macroscopic findings of the capsules suggest the development of a malignoma within the last 3 years.