Introduction/Background Phyllodes tumors are rare fibroepithelial tumors of the breast, accounting for less than 1% of malignant breast tumors. The association of PTs with heterologous sarcomatous differentiation is a rare phenomenon, accounting for 1.3% of all phyllode tumors—only a few previously reported cases in English literature.

Methodology We report eleven cases diagnosed at our institute between 2005 and 2022. Patients’ demographic data and clinical details were obtained from the medical records. Histopathology and immunohistochemical studies were analyzed.

Results Out of 41 cases of PT, 18 were found to be MPT, of which 11 cases showed heterologous differentiation in the form of angiosarcoma in 2 cases, liposarcoma in 5 patients, and osteosarcoma in 3 patients and chondrosarcoma in one patient.

The median age at the moment of diagnosis was 43.5 years. The median size was 7.4 cm. Surgery was performed in all cases. Eight patients underwent adjuvant radiotherapy.

The mean Follow-up was 12 months with 2. The mean survival duration was 2.3 years (1–5 years). Based on the DFS curves, heterologous elements (P = 0.024) were independent prognostic indicators.

Conclusion Because of the paucity of data, there is no clear treatment protocol, with uncertain prognosis. Proper diagnosis and subtyping of the sarcomatous component are essential for deciding the correct treatment modality and prognostication of the disease.

Disclosures ‘The author declares that (s)he has no relevant or material financial interests that relate to the research described in this paper’.