Sections show an infiltrative, hypercellular high-grade tumor with a lobular architecture, composed of pleomorphic spindle to epithelioid cells. These cells display hyperchromasia, prominent nucleoli, and brisk atypical mitoses. The tumor shows biphasic matrix production: disorganized, lace-like osteoid like material is intimately admixed with distinct areas of malignant cartilage. This chondroid component features a basophilic myxoid matrix containing atypical cells within lacunar spaces. Geographic coagulative tumor necrosis is present. Picture is consistent with unclassified spindle cell sarcoma. Marker study (S-100, SOX-10, p63, SMA, SATB2 and KI-67) is recommended for definitive subtyping.
Right-sided facial swelling secondary to a destructive, lytic lesion of the right mandible with cortical erosion and calcifications.
Soft tissue fragments collectively measured 8x7.5x2.5 cm, the largest measured 4x3.5x2.5 cm.
Right mandibular bony lesion, excision: