Pathology report:

1. Gross:  Specimen consists of multiple gray-brown soft and bony tissue.
2. Microscopic: Sections reveal blood-filled cystic spaces without endothelial lining surrounded by fibro-myxoid stroma containing many osteoclasts and chondroid areas formed of fibrillary elastic type of cartilage with bland cytologic features.

Diagnosis is Aneurysmal bone cyst.