Extraosseous osteogenic sarcoma--a rare pediatric malignancy: case report and review of the literature

Extraskeletal cartilaginous, osseous, and chordoid tumors in children and adolescents

Extraskeletal cartilaginous, osseous, and chordoid tumors are extraordinarily rare in children and adolescents. These lesions are diagnostically challenging due to their rarity and their overlap with metastatic osteosarcoma, reactive or metabolic calcifying and bone-forming masses, various pseudosarcomatous proliferations such as myositis ossificans, and other rare genetic or metabolic disorders. This article reviews the clinicopathologic features and differential diagnosis of extraskeletal cartilaginous, osseous, and chordoid neoplasms in the first two decades of life and highlights the use of diagnostic adjuncts.

Benign calcifying fibrous-myofibroblastic tumor mimicking myositis ossificans in a 22-month-old girl

Myositis ossificans circumscripta (MOC), with nonneoplastic heterotopic bone formation in soft tissue and skeletal muscle, is rare in children. Extraskeletal osteosarcoma is a very rare malignant mesenchymal neoplasm of soft tissues in children. At onset, it may be difficult to distinguish MOC from a musculoskeletal infection or neoplasm, particularly in the absence of trauma, and a biopsy is frequently required. However, differentiating MOC from malignant neoplasm is imperative. We describe the case of a 22-month-old girl who presented with a benign fibrous-myofibroblastic tumor mimicking MOC. However, extraskeletal osteosarcoma was also considered in the differential diagnosis due to the absence of attachment of the lesion to the skeleton. Pathologic findings after a previous needle biopsy and posterior marginal resection exclude both differential diagnoses. Close follow-up during 3 years postoperatively showed no signs of recurrence.

Extraosseous osteosarcoma in Ibadan: case series over a 20-year period

Extraosseous osteosarcoma (EOO) is a rare form of sarcoma. There have been few reports of cases and outcome from an African population.Out of 112 cases of sarcomas seen at the UCH, Ibadan between 1986-2005, 5 were EOO. All presented late on account of initial excision without histology and outcomes were poor. EOO occurs in the black population of Sub-Saharan Africa. The outlook for these patients is still bleak.

A chemosensitive pediatric extraosseous osteosarcoma: case report and review of the literature

Osteosarcoma arising in soft tissues is exceedingly rare in children. The tumor most often affects older adults, involves the lower extremity, responds poorly to chemotherapy, and carries a grave prognosis. The authors describe a 12-year-old girl with an extraosseous osteosarcoma of the left sternocleidomastoid muscle with pulmonary metastases. The patient responded well to neoadjuvant chemotherapy and remains disease-free nearly 3 years after her initial diagnosis. The authors review available information about this disease in children and adults. Children with extraosseous osteosarcoma may have a more favorable response to treatment than adults; thus, a curative approach using combined modality therapy appears warranted.

Malignant and benign bone tumors

The authors have intentionally included some confusing examples to demonstrate that the imaging findings of benign and malignant pediatric bone lesions are not always pathognomonic. The radiologist's role is to recognize malignant bone lesions and encourage the prompt referral of these patients to an appropriate institution for biopsy and treatment. The radiologist must also be able to identify benign lesions and help determine whether these lesions require biopsy and intervention or simply observation.