RESUMO
BACKGROUND: Peripheral primitive neuroectodermal tumors (PNET) belong to the rare family of primary bone neoplasms. Recent clinicopathological studies have revealed that Ewing's sarcoma and PNET have overlapping features and they are now included in the same classification, the Ewing's sarcoma family of tumors (EFTs). PNET have a marked predilection for the extremities and are very rare in the pelvis. These tumors can occur at any age with a peak of incidence in the second and third decades but are very rare in patients over 40 years. CASE REPORT: We report the case of a 69-year-old man with PNET sarcoma. Outcome was favorable after combined modality treatment including chemotherapy based on the Memphis protocol - adapted from that used for Ewing's sarcoma in children - and surgery. CONCLUSION: Our case is uncommon because of the age at diagnosis, the fortuitous way of revelation, and the choice of dose-intense chemotherapy adapted from the Memphis protocol (cyclophosphamide- and doxorubicin-based) for children, which was efficient and safe. It supports the fact that an adult, and even an old patient, with good physical status, may be treated safely and radically even with dose-adapted aggressive chemotherapy.