[P-31] Malignant phyllodes tumour of the breast with heterologous osseous differentiation
Muhammad Syah Misuari Sabirin1, Hasrayati Agustina1 and Maman Abdurahman2
- Department of Anatomical Pathology, Faculty of Medicine, Universitas Padjadjaran, Hasan Sadikin Hospital, Bandung, Indonesia
- Department of Surgical Oncology, Faculty of Medicine, Universitas Padjadjaran, Hasan Sadikin Hospital, Bandung, Indonesia
Background: Phyllodes tumour of the breast is one of the fibroepithelial neoplasms that shows proliferation of both epithelial and mesenchymal component. In malignant condition, the diagnosis can be established by the existence of malignant heterologous component even if common features are absence. This case report demonstrates a case of malignant phyllodes tumour with heterologous part of an osseous differentiation.
Case Presentation: We reported a case of 43-year-old woman who came to the hospital with lump on her left breast. The lump had been appeared for more than a year. The nodule size was 6 x 4 x 3 cm, firm, and followed with ulceration of the skin. The patient then underwent radical mastectomy for her condition. Histopathology result showed tumour mass with round to spindle cells that occurred with foci of osseous differentiation composed of osteocytes. The nuclei appeared pleomorphic and hyperchromatic with abundant mitosis. Immunohistochemistry results exhibited a negative CK and below 40% of Ki67 index.
Discussion and Conclusion: Malignant phyllodes tumour differs from its benign counterparts from the nature of its growth. It is diagnosed if there is any appearance of malignant heterologous element, which in this case appears as an osseous differentiation. The stromal overgrowth also supports the diagnosis of this tumour, showed by the absence of epithelial elements proved by negative CK marker.