Phyllodes tumour with heterologous sarcomatous differentiation: Case series with literature review

• Phyllodes tumours with heterologous sarcomatous differentiation are extremely rare.
• We report 2 such cases in females in their fifties and describe the clinical presentation, diagnostic investigations and management with 2 year follow-up.
• There is limited literature to guide adjuvant therapy and prognosis of phyllodes tumours with heterologous sarcomatous differentiation.

IntroductionPhyllodes tumours are rare fibroepithelial malignancies of the breast, accounting for less than 1% of malignant breast tumours. Further malignant differentiation of phyllodes tumours can occur, resulting in cases of extremely rare heterologous sarcomatous differentiation.Presentation of caseTwo females in their fifties were diagnosed with malignant phyllodes tumour associated with heterologous sarcomatous differentiation. The first patient, aged 50 had phyllodes tumour with chondrosarcoma, osteosarcoma and ductal carcinoma-in-situ. The second patient, aged 53 had phyllodes tumour with osteosarcoma and liposarcoma.DiscussionThe association of phyllodes tumour and heterologous sarcomatous differentiation is rare, with only 4 previously reported cases in English literature. The paucity of evidence presents challenges in its management with uncertain prognosis and monitoring requirements for two aforementioned patients.ConclusionFurther case series and long-term follow up is required for accurate characterisation of phyllodes tumours with heterologous sarcomatous differentiation.