Extraskeletal osteochondroma is a variant of extraskeletal chondromas that are uncommon soft-tissue cartilaginous tumors. These tumors may undergo extensive enchondral ossification to form an extraskeletal osteochondroma. This report describes the case of a 39-year-old Japanese man with an extraskeletal osteochondroma arising on the plantar aspect of the foot.

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...

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...

Extraskeletal chondrosarcoma in anterior mediastinum is very rare. A 45-year-old male patient was admitted to the hospital with precordial chest pain. A large and well-shaped mass in the anterior mediastinum was seen radiologically, and there was a clearly compression of the heart by the mass. The lesion was totally resected, and extraskeletal mediastinal chondrosarcoma was histopathologically ...

Extraskeletal osteochondroma, an infrequently encountered benign lesion, is described in 1 patient who presented with a slow-growing, relatively painful mass on the dorsal side of his right foot, in the 3rd toe web. Radiographs and magnetic resonance imaging studies demonstrated a radio-opaque extraskeletal mass. Excision biopsy revealed a well-defined and lobulated, firm, calcified, extraskele...

We describe a unique case of a low-grade extraskeletal osteosarcoma revealing both histologic and radiologic features reminiscent of parosteal osteosarcoma. The tumor, which had been present for 10 years, occurred in the left axilla of a 74-year-old black woman. To date, all the published cases of extraskeletal osteosarcoma have been high-grade neoplasms; to our knowledge, this is the first rep...

Background. Ewing sarcoma (ES) is a high-grade malignant tumor that has skeletal and extraskeletal forms and consists of small round cells. In the head and neck region, reported localization of extraskeletal ES includes the larynx, thyroid gland, submandibular gland, nasal fossa, pharynx, skin, and parotid gland, but not the external ear canal. Methods. We present the unique case of a 2-year-ol...

BACKGROUND Extraskeletal myxoid chondrosarcoma is a unique and distinct clinicopathological entity in terms of its origin, morphology, and biologic behavior. Despite being a slow-growing tumor, it has a high rate of local recurrences and history of metastases to uncommon sites like the mandible, liver, retroperitoneum, right ventricle, pancreas, and central nervous system. Here, we report a ver...