Beyond the Bone: A Case Report and Review of Literature of Extraskeletal Chondroblastic Osteosarcoma of the Scalp

Extraskeletal osteosarcoma (EOS) of the scalp is an extremely rare malignant mesenchymal tumor that accounts for approximately 1 to 2% of all soft tissue sarcoma and 2 to 4% of all osteosarcoma. A 40-year-old man presented with painless swelling on the left side of the scalp for 3 months and right-side limb weakness for 10 days. The patient underwent surgery and the postoperative histopathology report was suggestive of chondroblastic osteosarcoma of the scalp. The patient received five cycles of Adriamycin-based systemic therapy. A response assessment imaging was done, which was suggestive of partial response. Osteosarcoma is chemotherapy- and radiotherapy-resistant tumor; hence, it requires a combined modality approach. Complete surgical excision with adequate surgical margin followed by adjuvant chemotherapy and radiation therapy proved to be one of the optimal treatment modalities.