Clinical and pathologic study of two siblings with osteosarcoma

Familial occurrence of telangiectatic osteosarcoma is rare. A sister and a brother developed telangectatic osteosarcoma at the age of 11 and 12 respectively. The tumors occurred in the metaphysis and epiphysis of the distal left femour and in the 9th left rib respectively. In their family there was no previous bone cancer or retinoblastoma. Although the local behavior was very aggressive, the clinical courses were relatively indolent in both cases, thanks to the high chemo-sensitive of the telangectatic osteosarcoma. The histologic features were similar, showing anaplastic tumor cells producing osteoid and proliferation of blood cavities. Such malignancies within a family suggests the presence of a genetic factor. We discuss possible explanations for familial aggregation of osteosarcoma, citing genetic factors.