We present the case of an intra-articular osteoid osteoma at the femoral trochlea. Intra-articular osteoid osteoma can present a diagnostic challenge both clinically and with imaging because it presents differently from the classic cortical osteoid osteoma. Given the lesion's proximity to overlying cartilage, the patient underwent resection of the lesion with osteochondral autograft transplanta...

introduction: osteoma is a benign tumor rarely found in the paranasal sinuses.   case report: a 30-year-old female presented with an 8-month history of proptosis of the right eye that was progressing slowly. she was diagnosed with ethmoid osteoma and managed with collaborative surgery at the ophthalmology and otolaryngology departments. after surgery, the patient suffered visual loss that was m...

Canine extraskeletal osteosarcomas are extremely rare tumors. Over a period of 25 years at the Animal Medical Center, approximately 1,000 cases of skeletal osteosarcomas have been diagnosed. During the same period 11 cases of extraskeletal osteosarcomas and three extraskeletal chondrosarcomas were diagnosed. Tumors of the mammary gland were excluded. Extraskeletal osteosarcomas were found in th...

Osteochondromas found within the soft tissue without osseous or intra-articular involvement are better described as extraskeletal osteochondromas. They are slow-growing, benign, osseous tumors, and are often misdiagnosed as conventional osteochondromas. Though extraskeletal osteochondromas are rare, they typically affect the digits of the hands or feet. We present a patient with a giant symptom...

Osteoid osteoma is a benign bone tumor, which rarely occurs in the skull, and often causes local pain that is worse at night, characteristically relieved by aspirin. Giant osteoid osteoma in the occipital bone is uncommon. We present a case of a 42-year-old female with an osteoid osteoma of the occipital bone that was totally resected. We discuss the clinical presentation, radiographic findings...

Extraskeletal osteosarcoma is an uncommon high-grade malignant soft tissue sarcoma. Well-differentiated extraskeletal osteosarcoma is thought to have a better prognosis than classical extraskeletal osteosarcoma, but dedifferentiation after recurrence has also been reported. We present a case of a primary retroperitoneal extraskeletal osteosarcoma in a 62-year-old Japanese woman. Abdominal CT re...

Only seven cases of osteoma arising in the middle turbinate have been reported to date. We report the eighth case, involving osteoma in the middle turbinate of a child. This young boy was initially examined at the age of nine for the main complaint of nasal obstruction. Although a large osteoma with a maximum diameter of 30 mm was observed on computed tomography (CT), the patient was only obser...

Introduction. Osteoma is a benign, slowly growing, asymptomatic, osteogenic neoplasm. Osteoma of a bone other than the skull and facial bones is extremely rare. An extremely rare case of parosteal osteoma is reported. Case Presentation. A 51-year-old woman presented with a large mass in the left supraclavicular fossa. Radiographs and computed tomography revealed a well-defined, 9 × 6 cm, lobed ...

Osteoid osteoma of the spine is a relatively rare bone-forming tumor. Pain that is worse at night and relieved by aspirin and muscle contracture are the most characteristic symptoms of spinal osteoid osteoma. Although radicular pain occasionally occurs in spinal osteoid osteoma, spinal cord and nerve root compression is absent in most cases. Although radicular pain appears to be associated with...