Surface osteosarcomas: Diagnosis, treatment and outcome

Abstract

Surface osteosarcomas are a rare form of osteosarcomas accounting for around 3-6% of all osteosarcomas. Three major groups of surface osteosarcomas are parosteal, periosteal and the high grade surface osteosarcomas. Of these, the parosteal osteosarcoma is the most common. Parosteal and periosteal osteosarcomas are distinct clinical entities and it is important to identify the clinicoradiological differences between the two types. Surface osteosarcomas occur at a later age as compared to conventional osteosarcomas. The classical site is the lower end of the femur followed by the upper end of the tibia and upper end of humerus, in that order. The periosteal variant affects the tibia more commonly than the parosteal variety. Neo-adjuvant chemotherapy is the standard of care for high grade surface osteosarcomas. Parosteal osteosarcomas, being low grade lesions, can be treated by upfront wide excision without adjuvant systemic therapy. Controversy prevails over the need for chemotherapy in periosteal osteosarcomas, which are intermediate grade lesions.

Improving generalization of deep learning models for diagnostic pathology by increasing variability in training data: experiments on osteosarcoma subtypes

“…The exact cause of the decline is unclear. Our hypothesis is that parosteal subtype arises from the surface of the bone, it is generally well differentiated of a lower stage (stage I and II) [16] . In the images we have selected, there are several images with areas of chondroid differentiation.…”

“…Osteosarcoma subtypes include conventional variants, surface types and other variants like small cell, extra-skeletal and secondary osteosarcoma like complicating Paget’s disease. Conventional variants include osteoblastic, chondroblastic, telangiectatic and fibroblastic subtypes [15] , and surface osteosarcomas include periosteal and parosteal and high-grade surface types [16] . In Figure 1, we show the different subtypes of osteosarcoma.…”

“…The copyright holder for this this version posted September 18, 2020. ; https://doi.org/10.1101/2020.09.10.20192294 doi: medRxiv preprint complicating Paget's disease. Conventional variants include osteoblastic, chondroblastic, telangiectatic and fibroblastic subtypes [15] , and surface osteosarcomas include periosteal and parosteal and high-grade surface types [16] . In Figure 1, we show the different subtypes of osteosarcoma.…”

Triple primary malignancies of surface osteosarcoma of jaw, myelodysplastic syndrome and colorectal cancer as a second primary cancer detected by PET2‑[18F]‑fluoro‑2‑deoxy‑D‑glucose positron emission tomography: A case report

“…Therefore, we should consider the possibility of parosteal OS with partial dedifferentiation to high-grade OS. Namely, all of the surface OSs of jaw tend to develop approximately 20–30 years old ( 39 ). Among those, parosteal OS occurs at a relatively higher rate in elderly patients, similar to our patient ( 38 ).…”

Parosteal osteosarcoma with focal fatty metaplasia: A case report

“…Grossly, the tumor appears as a hard lobulated mass attached to the underlying external layer of periosteum, and may contain nodules of cartilage within the substance of the tumor or an incomplete cartilage cap at the surface [4] . Microscopically, PO is characterized by hyalinized fibrous stroma with a low cell content without substantial nucleus polymorphism and variably dense bony trabeculae [3] .…”