A Rare Pediatric Example of Subcutaneous Extraskeletal Osteosarcoma

Abstract

Primary extraskeletal osteosarcoma is an exceedingly rare malignant neoplasm that accounts for approximately 1% of soft tissue sarcomas and most often occurs in the deep soft tissues of adults. Extraskeletal osteosarcoma is characterized by the production of osteoid, bone, and/or chondroid matrix. The diagnosis of extraskeletal osteosarcoma requires careful radiologic and clinical correlation to ensure that the patient does not have an underlying bone primary. This is a case report of primary subcutaneous extraskeletal osteosarcoma arising in the thigh of a 15-year-old girl with a complex karyotype, and the morphologic differential diagnosis is reviewed.

Pancreatic Extraskeletal Osteosarcoma Metastasizing to the Scalp

“…Over 70% patients experience local recurrence and metastasis. The overall 5-year survival is reported to range from 25% to 77% and patients with metastatic lesions have a morality rate over 60% 3 7 . In one case series, the median survival time was measured as 8 months for metastatic ESOSs with doxorubicin-based chemotherapy 8 .…”

“…Extraskeletal osteosarcoma (ESOS) is an aggressive mesenchymal soft-tissue neoplasm accounting for 1% of all soft-tissue sarcomas and 2% to 5% osteosarcomas 1 2 3 . It can be diagnosed when the soft-tissue tumor appears with osteoid or cartilage matrix in a sarcomatous pattern but lacks any underlying bony connection 4 .…”

“…It clinically manifests as a painless lesion in the lower extremities, most commonly occurring in the muscles of the thigh followed by the retroperitoneum and upper limb 1 6 7 . The lung is the most common site for the metastasis of ESOS followed by the regional lymph nodes 3 8 . The reported skin metastases from ESOS have been exceedingly rare 1 6 .…”