Summary

We report the case of a 12-year-old girl with a strong family history of malignancy who presented with immature teratoma and gliomatosis peritonei. Despite first and second line chemotherapy, the disease ran an unusually refractory course. Although the presentation was not the typical tumour presentation of Li–Fraumeni syndrome (LFS), we proceeded to undertake tumour genetic testing of the patient and her parents. LFS was diagnosed in this patient and her father with a sequence variation of CGG>TGG, R248W, which is one of the most common transcriptionally inactive mutations detected in LFS. Genetic counselling was offered to the father. A tumour screening programme and genetic screening for the p53 gene mutation for the surviving family members can be offered once consent is obtained from the father. This case illustrates the importance of cancer genetic study, even if the tumour presentation is not typical for any familial cancer syndrome.