Cervical vertebrae metastatic sarcoma with osteoclast- like giant cells originating from malignant breast phyllodes tumor in thecontext of benign recurrent phyllodes: a case report

Background:Phyllodes tumor is a biphasic tumor with epithelial and stromal components. These tumorshave an unpredictable clinical outcome ranging from benign with local recurrence tomalignant and metastasis. The stromal component can undergo cartilaginous, bony andmuscular metaplasia. Breast tumors especially of stromal origin with multinucleatedosteoclast-like giant cells have rarely been reported.Case presentation:A 48-year-old woman presented with benign phyllodes tumor of breast with foci ofosseous metaplasia. Following multiple recurrences, it converted to high grademalignant phyllodes which ultimately metastasized to the cervical vertebrae.Conclusion:Breast phyllodes tumors are rare fibroepithelial neoplasms with unpredictable behaviorand a tendency for recurrence. The recurrence can show more malignant featuresthan the original tumor. The malignant transformation is usually sarcomatoid withfibrosarcomatouscharacteristics and rarely with components such as liposarcoma, rhabdomyosarcoma,chondrosarcoma or osteosarcoma. Cases of primary malignant breast phyllodes tumor withosteoclast-like giant cells have seldom been reported and their nature is yet unknown.Here we present a rare case of cervical vertebrae metastatic sarcoma withosteoclast- like giant cells originating from malignant breast phyllodes tumor.Keywords: Phyllodes tumor, metastasis, cervical vertebrae, sarcoma with osteoclastlikegiant cells.