Retinoblastoma is a rare cancer of the eye, usually diagnosed within the first year of life. Although it is rare, it is the most common primary eye tumour of childhood. Life expectancy following treatment is now excellent, but survivors with heritable retinoblastoma have an increased risk of a second malignant neoplasm. A second neoplasm, which often occurs in the irradiated field of the original tumour, has become the most significant threat to the survival of these patients. This is attributed to both genetic and treatment factors. The Rb1 gene is one of the tumour suppressor genes, so patients with hereditary retinoblastoma have a germ-line and lifetime predisposition to non-ocular cancers.
Between 1971 and 1981 childhood-cancers were treated with external beam x-ray therapy at Rikshospitalet, Norway, despite the fact that megavoltage therapy was available at the time and the consequences of using conventional irradiation were well known. In 1998 the Norwegian State took initiative and granted 15 children financial compensation because of complications due to this treatment.We report the case of a woman who was cured of her retinoblastoma but later developed a second non-ocular tumour that subsequently metastasized to the lungs. She was one of the 35 children treated for retinoblastoma between 1971 and 1981 in Norway. Here case is interesting because she did not only develop a secondary neoplasm in the irradiated field. She developed a type of sarcoma which is seldom observed in the irradiation field, leiomyosarcoma. Only 23 cases have previously been reported in the literature.