[Li-Fraumeni syndrome].

Li-Fraumeni syndrome is a rare genetic disorder predisposing the individual to multiple different cancer types, caused by a germline mutation of the TP53 or CHEK2 genes inherited in an autosomal dominant manner. We hereby describe the case of a family with Li-Fraumeni syndrome. An asymptomatic 40-year-old female was diagnosed with primary lung leiomyosarcoma (T3N0), adenocarcinoma (T1aN0), and inflammatory myofibroblastic tumor, which were surgically removed without further treatment. Twenty months later she underwent surgery for retroperitoneal liposarcoma and even though she received adjuvant chemotherapy, deceased shortly after. Due to family history, the patient underwent TP53 mutation testing, using peripheral blood genomic DNA, which identified a heterozygous, likely pathogenic missense mutation (c.722C>G p.Ser241Cys) in case of the mother and her son. Three years after the patient's death, her 17-year-old son was diagnosed with a 3.5 cm osteosarcoma of the right second rib, which was surgically removed, followed by adjuvant chemotherapy. However, despite treatment, he deceased after two years. Throughout four generations of the patient's family, 10 malignant tumors (stomach-, breast-, 2 lung-, and colon cancer, leukemia, leiomyosarcoma, liposarcoma and 2 osteosarcoma) were diagnosed with a mean age of 43.2 (13-70 years) years. The simultaneous appearance of primary lung leiomyosarcoma, inflammatory myofibroblastic tumor and adenocarcinoma in the same organ is extremely rare. When possible, surgical resection should be carried out. Genetic testing for TP53 is recommended when family history is suggestive of Li-Fraumeni syndrome. Prognosis remains poor. Orv Hetil. 2019; 160(6): 228-234.