Parosteal osteosarcoma, a distinct entity in which the neoplasm arises on the bone surface. An intramedullary located lowgrade osteosarcoma,which is differentiated like a parosteal osteosarcoma,is histologically indistinguishable from the parosteal variant. Parosteal osteoid sarcoma, sometimes referred to asjuxtacortical osteogenic sarcoma, is a rare malignant bone tumor which must be differentiated from an osteosarcoma clinically, roentgenologically, and histologically. It arises from the surface of the bone, namely the outer layer of the periosteum. Diagnostic and treatment problems with parosteal osteosarcoma. Of these, the parosteal osteosarcoma is the most common. Epidemiology it is the most common type of juxtacortical or surface osteosarcoma and accounts for 5% of all osteosarcomas. The surgical treatment of parosteal osteosarcoma in long bones. There are numerous types of primary osteosarcoma, including intramedullary high grade, telangiectatic, low grade, small cell, osteosarcomatosis, and gnathic, surface intracortical, parosteal, periosteal, and highgrade surface, and extraskeletal. Osteosarcoma os is a malignant spindle cell sarcoma in which the malignant cells produce osteoid or bone in the background of a sarcomatous stroma. Periosteal osteosarcoma is defined by the world health organization as an intermediategrade, malignant, cartilaginous, and boneforming neoplasm arising on the surface of bone. Parosteal osteosarcoma is a subtype of osteosarcoma and arises from the outer layer of the periosteum. The classic or socalled conventional osteosarcoma develops in the medullary cavity of the metaphysis of long bones.
Femoral parosteal osteosarcoma 18 years after its discovery. Survival rates can give you an idea of what percentage of people with the same type and stage of cancer are still alive a certain amount of time usually 5 years after they were diagnosed. This is the third subtype of osteosarcoma arising on the surface of the bone. Parosteal osteosarcoma, or juxtacortical osteosarcoma, is a rare form of osteosarcoma that develops at the bone surface, but has a better prognosis than other conventional osteosarcomas. A central cancellous osteosarcoma is a central destructive lesion with varying amounts of osteoid matrix, is radiographically discernable. This article documents the sixth reported case of parosteal osteosarcoma. Parosteal osteosarcoma parosteal os is the most common type of juxtacortical os, accounting for approximately 5% of all os cases and typically manifesting in. A preexisting bone lesion suggestive of pagets disease of bone. This is an extremely rare location for a parosteal osteosarcoma. The ultrastructure of conventional, parosteal, and.
The most commonly affected sites, in descending order, are the distal femur typically the posterior surface, the proximal humerus, the proximal femur, the proximal tibia, and the proximal ulna. The importance of making the diagnosis of periosteal osteosarcoma cannot be understated owing to the distinct natural history and that resection alone is a standard treatment for parosteal osteosarcoma, while resection and adjuvant chemotherapy are standard treatments for highgrade surface osteosarcoma. We had experienced a parosteal osteosarcoma involving the flat bone, the scapula of a 21yearold man. A staging system is a standard way for the cancer care team to sum up the extent of the cancer. The radiologic appearance of periosteal osteosarcoma is a broadbased surface soft. Os is now classified into three main subtypes parosteal, periosteal, and highgrade surface osand these are further categorized by their histologic features and histologic grade. Parosteal osteosarcoma with pulmonary metastases in a cat. Bizarre parosteal osteochondromatous proliferation bpop, also known as noras lesion, is an uncommon, benign bone tumor that grows on the surface of the bone. Parosteal osteosarcoma parosteal osteosarcoma is a subtype of osteosarcoma and arises from the outer layer of the periosteum. Osteo boneosteoid tissue sarcoma malignant tumour of connective tissue 020412 dr. Rare repeated recurrence of parosteal osteosarcoma. Parosteal osteosarcoma is the least malignant of the osteogenic tumors, and typically carries a relatively. Parosteal osteosarcoma is a low grade, well differentiated fibroblastic tumor that produces boneosteoid immature woven bone.
Mdm2 and cdk4 expression in periosteal osteosarcoma. It most commonly occurs in young women over the metaphyseal region, especially the long bones near the. Most common type of juxtacorticalsurface osteosarcoma. Plain films and computed tomography distinguish the radiolucent area between the tumor and the bone cortex. Parosteal and periosteal osteosarcomas are distinct clinical entities and it is important to identify the. In this retrospective clinical study, 7 cases of parosteal osteosarcoma of the bone have been analyzed. However, at other times, it can be painful and lead to bone deformity. Parosteal osteosarcoma atlas of musculoskeletal oncology. Plain radiograph showed broadbased, welldefined radiodense lesion at the scapula. Periosteal osteosarcoma radiology reference article. Because of its rarity, parosteal osteosarcoma remains primarily a diagnosis to be excluded in the hand. Surface osteosarcomas are a rare form of osteosarcomas accounting for around 36% of all osteosarcomas. A poorly defined softtissue component distinct from the ossific matrix is the most distinctive feature of highgrade parosteal osteosarcoma. Parosteal osteosarcoma is a rare malignant bone tumor arising from the bone cortical surface.
The comparative study of parosteal and conventional osteosarcomas revealed a marked difference in the cell population. In contrast to other osteosarcomas, parosteal osteosarcomas arise from the bones surface with less than 25% involvement of the medullary cavity. We report two cases mimicking an osteochondroma, radiologically and histologically and propose an explanation. It has not been described to arise from sites other than the major tubular bones. Parosteal osteosarcoma of the humerus j request pdf. However, fibrous or cartilaginous tissue may coexist or even predominate.
Parosteal osteosarcoma is a welldifferentiated variant of osteosarcoma that affects the surface of the bone. Osteosarcoma may also occur as a secondary lesion in association with underlying benign conditions. Periosteal osteosarcoma is a form of surface osteosarcoma. Parosteal osteosarcoma is a lowgrade osteosarcoma, which occurs on the surface of the bone. Pdf parosteal osteosarcomas are rare, lowgrade juxtacortical variant of osteosarcoma, especially in the jaws, representing 1. Full text full text is available as a scanned copy of the original print version. This article documents the sixth reported case of parosteal osteosarcoma arising in the hand. Survival rates for osteosarcoma american cancer society. Paul chihhsueh chen, md, phd parosteal osteosarcoma is a rare malignant bone tumor arising from the bone cortical surface. Parosteal osteosarcoma radiology reference article. It is usually found at the cortical surface of long bones in the metaphyseal region.
Get a printable copy pdf file of the complete article. Radiographs and ct demonstrate a parosteal osteosarcoma of the distal femur. Osteosarcoma presents most commonly as a conventional intramedullary type or, less frequently, as rare variants, including periosteal, parosteal. Pdf parosteal osteosarcoma of the talus hans schild. Parosteal osteosarcoma, juxtacortical osteosarcoma. Parosteal osteosarcoma used in the following article. He reports that he sustained a noncontact twisting injury to the knee 7 months ago while playing softball. Juxtacortical osteosarcomas are rare 8%10% of all osteosarcomas1 and can be classified into. Pdf periosteal osteosarcoma is a rare variant of osteosarcoma.
Three major groups of surface osteosarcomas are parosteal, periosteal and the high grade surface osteosarcomas. The parosteal osteosarcoma is usually g1 and the periosteal. Periosteal osteosarcoma is an intermediategrade chondroblastic osteosarcoma, accounting for less than 2% of all osteosarcomas and it occurs extremely rarely in the jaws. The full text of this article is available in pdf format. It is a surface lesion without evidence of medullary involvement. They cant tell you how long a person will live, but they may help give you a better understanding of how likely it is. Osteosarcoma is a malignant neoplasm characterized by direct formation of bone or osteoid by the tumor cells. Gnas mutations are not detected in parosteal and lowgrade. Late relapsing parosteal osteosarcoma has been reported very rarely. Radiologically, it manifests as an ossified mass with irregular mineralization and is characterized by a cleavage plane with the underlying cortex.
All 17 highgrade lesions evaluated with mr imaging were of predominantly high signal intensity on t2weighted images. Parosteal osteosarcoma is a lowgrade, malignant, boneforming tumor that arises on the surface of bone. John hunter is a professor in the department of radiology musculoskeletal section at uc davis school of medicine. However, the implications of this diagnosis and the fact that it can occur in the hand must be considered carefully in each case. Herein, we present a case of late relapsing low grade parosteal osteosarcoma after 15 years in popliteal cavity after advising tumor excision, removal of the organ involved, and the placement of prosthesis. It most commonly occurs in young women over the metaphyseal region, especially the long bones near the knee joint. Also called juxtacortical osteosarcoma outside of the periosteum ages 30 60 years, either no gender preference or female predominant arises in metaphyses of long bones. Parosteal osteosarcoma is a slowgrowing malignant bone tumor most commonly occurring in young women.
Osteosarcomas arising on the surface of the bone have been classified into three subgroups, two of which, parosteal osteosarcoma and periosteal osteosarcoma, tend to have a much better prognosis than conventional osteosarcoma. We focus on parosteal os and dedifferentiated parosteal os. A previously performed radiotherapy for other cancer conditions. Epidemiology it is the second most common type of juxtacortical or surface osteosarcoma after parosteal osteosarcoma and accounts for 1. Parosteal osteosarcoma occurs in the periosseous tissues.
Mri findings in parosteal osteosarcoma diagnostic and. What are the risk factors for parosteal osteosarcoma. Periosteal osteosarcoma po is a rare primary malignant bone tumor and a variant of osteosarcoma. Bizarre parosteal osteochondromatous proliferation.
We present a rare case of mandibular periosteal osteosarcoma. This neoplasm also has been called juxtacortical os teogenic sarcoma, parosteal osteogenic sarcoma, ossifying par osteal sarcoma, juxtacortical osteosarcoma, and parosteal os. Parosteal os is a lowgrade sarcoma of the bone surface in which hypocellular spindlecell stroma forms welldifferentiated osseous trabeculae. The stage of an osteosarcoma is based on the results of physical exams, imaging tests, and any biopsies that have been done, which are described in tests for osteosarcoma. Predisposing factors the risk of parosteal osteosarcoma is linked to the following factors. Get a printable copy pdf file of the complete article 1. Pdf our purpose was to describe a rare juxtacortical bone sarcoma with deceptively benign, osteochondromalike histologic characteristics.