“Skip” metastases in osteosarcoma

Abstract

Careful study of 40 cases of osteosarcoma without evidence of multifocal disease, pulmonary metastasis, or history of exposure to predisposing factors has given histologic evidence of microscopic foci of osteosarcoma separate from the primary focus of osteogenic sarcoma. These "skip" lesions are to all pathologic examination completely separate from the primary focus of osteogenic sarcoma. They are more often found proximal to the primary, both intraosseously and transarticularly. Histologically, these "skips" represent areas of osteosarcoma which in many cases are a less-differentiated form of the tumor. The natural history of such tumors with "skips" following ablative surgery is an increased incidence of local recurrence and subsequent pulmonary metastases. Following open biopsy which demonstrated osteosarcoma, a hip disarticulation was performed. At dissection of the specimen, the tumor was found to involve the distal epiphysis and metaphysis and extend proximally to the junction of the distal and middle thirds of the diaphysis. A 1-cm diameter cortical lesion resembling a "blister)' was found at the junction of the proximal and middle thirds of the diaphysis 18 cm above the margin of the primary lesion (Fig. 1A and B). There was no gross or microscopic connection between this and the primary lesion in the distal femur. Histologically, this lesion appeared to be a separate focus of osteogenic sarcoma. Review of the literature at that time revealed several discussions of the entities known as multicentric osteosarcoma and/or metastatic osteosarcoma. 1*69g-11,16

Synchronous Multifocal Osteosarcoma Involving the Skull Presenting With Intracranial Hemorrhage -Case Report-

“…8,10,18) Metastasis via the vertebral venous plexus system may be a plausible mechanism of bone-to-bone metastasis without evidence of pulmonary metastasis. 7,9,15) Multifocal osteosarcoma can be classified according to histology, patient age, and time at presentation of multiple osseous lesions. 2) Type I patients are less than 18 years of age, with multiple histologically anaplastic osseous lesions appearing within 5 months of the initial presentation.…”

Sık görülen primer malign kemik tümörlerinde radyoterapinin yeri ve tedaviye genel yaklaşım

“…[6] Skip metastazlar, Enneking ve Kagan tarafından aynı kemikte, primer lezyondan anatomik olarak ayrılan, eş zamanlı, daha küçük tümör odakları veya eklemin diğer tarafında eşzamanlı daha küçük tümör odağı olarak tanımlanır. [10,11] Sistemik evreleme, akciğer ve kemik metastazları için bilgisayarlı tomografi (BT) ve radyonüklid kemik görüntülemeyi içermelidir (3).…”

MR imaging in staging of bone tumors

“…6). Enneking reported that it occurred in 20% of osteosarcoma cases, but it is actually not so common [10] . It is seen in highgrade lesions.…”