OWL: OCOSH Classification/Bone Diseases/Orthopaedic Oncology/Connective and Soft Tissue Neoplasms/Bone Neoplasms/Osteosarcoma/Juxtacortical Osteosarcoma

Juxtacortical Tumors eMedicine Orthopedics

Kimberly J Templeton, MD — 2008-04-07 23:29:55 GMT

Juxtacortical or surface tumors are broadly defined as those arising adjacent to the outer surface of cortical bone. These surface lesions may arise from any of the mesenchymal elements present along the bone surface or from the pluripotent cells found within the periosteum. However, in most cases, it is impossible to determine whether the sarcoma arose from within the periosteum or from other juxtacortical connective tissues, with secondary involvement of the periosteum. These tumors are composed of a variety of histologic tissue types. The most common types are those producing cartilage or bone.
Synonyms and related keywords: periosteal chondroma, periosteal chondrosarcoma, surface osteosarcoma, surface tumor, parosteal osteosarcoma, periosteal osteosarcoma, high-grade surface osteosarcoma
Author: Kimberly J Templeton, MD

Parosteal Osteosarcoma Pre-Test and Tutorial

Frassica & Sim — 2007-03-27 23:29:55 GMT

Section of Orthopedics Hyperguide

Parosteal Osteosarcoma Wheeless

Wheeless — 2007-03-28 23:29:55 GMT

Discussion: - parosteal osteosarcoma is a low-grade malignant bone tumor that usually occurs on the surface of the metaphysis of long bones; - arises between cortex and muscle as a low grade stage I-A surface tumor (ie does not initially invade underlying medullary canal); - most common in adolescents and yound adults; - parosteal osteosarcoma is distinguished from classic osteosarcoma by its much slower, less aggressive clinical course. - there is a low propensity to metastasize; - about 10% of parosteal tumors exhibit areas of dedifferentiation into high grade sarcoma & are thus considered stage IIb lesions. - tumor remains separated from normal bone, especially in the early stage; - extension into the underlying bone is associated with a higher incidence of dedifferentiation and pulmonary metastasis; - as growth continues, radiolucent zone between tumor & underlying bone may be obliterated as cortex becomes involved; - late in dz, tumor extends through the underlying cortex to invade medullary canal as well, converting to a stage Ib tumor; - invasion into the overlying displaced soft tissues is rare

Periosteal Osteosarcoma

Ritts et al — 2007-03-28 23:29:55 GMT

Ritts-GD; Pritchard-DJ; Unni-KK; Beabout-JW; Eckardt-JJ Clin-Orthop. 1987 Jun(219): 299-307 Periosteal osteosarcoma is a surface lesion without evidence of medullary involvement.

Periosteal Osteosarcoma Pre-Test and Tutorial

Frassica & Sim — 2007-03-27 23:29:55 GMT

Section of Orthopedics Hyperguide

High-Grade Surface OGS

2002-02-04 23:29:55 GMT

high grade periosteal OSA

Parosteal OGS

2002-02-04 23:29:55 GMT

parOSA

Parosteal sarcoma

2002-01-31 23:29:55 GMT

Radiology case 415-3222

Parosteal sarcoma

2002-01-31 23:29:55 GMT

Radiology case 471-3222

Periosteal OGS

2002-02-04 23:29:55 GMT

periosteal OSA