Extraskeletal osteosarcoma is a very rare tumor in humans and animals including rats. This paper describes a case of extraskeletal osteosarcoma observed in the glandular stomach of an aged female Fischer 344 rat. Grossly, a whitish solid mass was observed at the greater curvature of the glandular stomach. Histologically, the tumor consisted of both atypical polygonal and pleomorphic spindle-sha...

Osteochondromas are common benign tumors of cartilage and bone. They are usually found as contiguous bone with a cartilage cap at the end of the growth plate of long bones. Similar to structure are extraskeletal osteochondromas. However, unlike typical osteochondromas, extraskeletal osteochondromas are noncontinuous with bone. To our knowledge, all reported extraskeletal osteochondromas have be...

A 52 year old man developed an extraskeletal mesenchymal chondrosarcoma (ESMC) arising from the pleura. Clinically, the tumour mimicked a mesothelioma. Fine needle biopsy was consistent with the diagnosis of sarcomatoid mesothelioma. Histological examination of multiple tumour samples, supported by immunohistochemical characterization, made it possible to correctly diagnose extraskeletal mesenc...

Extraskeletal osteosarcoma is a rare soft tissue sarcoma and is in many ways distinct from skeletal osteosarcoma, including demographics, imaging feature, prognosis and management. We present a case of extraskeletal osteosarcoma arising from the retroperitoneum with dense ossification proved to be osteosarcoma by surgical resection. We describe the computed tomography (CT) and magnetic resonanc...

Osteoid osteoma is a rare entity in the tarsal bones especially in children. High degree of suspicion is needed for early diagnosis and delay in diagnosis can cause significant disability. Radiofrequency ablation (RFA) is safe, minimally invasive method especially to treat juxta-articular and inaccessible lesions. Atypical Osteoid osteoma can present with clinical features similar to that monoa...

• Osteoid osteoma is a benign bone tumor that usually presents in children and young adults characterized by local pain which is worse at night; occasionally the pain is referred to a site distant from the actual lesion. • Osteoid osteoma of the scapula should be considered in the differential diagnosis of neuralgic amyotrophy due to shared clinical features of pain, weakness, and atrophy aroun...

The authors present enhanced depth imaging optical coherence tomography (EDI OCT) and fundus autofluorescence (FAF) characteristics of a patient with bilateral choroidal osteoma and try to make a correlation between two imaging techniques. Two eyes of a patient with choroidal osteoma underwent complete ophthalmic examination. Enhanced depth imaging optical coherence tomography revealed a cage-l...

Osteoma is a benign osteogenic tumor arising from the proliferation of cancellous or compact bone. In the facial bones, both central and peripheral osteomas have been described in the literature. Peripheral type of osteoma is the most common variant in the mandible, which occurs on the cortical bone surface. We present a case of a fourteen year old boy who had swelling on right and left parasym...

Osteoid osteoma of the calcaneus is rare and frequently misdiagnosed as arthritis because of similar symptoms. In addition, radiographic findings may be nonspecific, and magnetic resonance imaging (MRI) may show a bone marrow edema and changes in adjacent soft tissue. A 19-year-old man presented with a 6-month history of persistent pain and swelling in the left hind foot; diagnostic computed to...

BACKGROUND Osteoid osteomas are benign bone-forming tumors characterized by local inflammation and pain. They are also characterized by a small osteolytic lesion (nidus). Spondylolysis is a defect of the pars interarticularis, which may lead to stress fractures, and is a common cause of low back pain in adolescence. Osteoid osteoma occurs predominantly in the posterior elements of the spine. Ma...