Background: Phyllodes tumors are rare fibroepithelial neoplasm of the breast, representing 0.3 to 0.5% of all female breast neoplasms. The term ‘‘phyllodes tumor” by the World Health Organization (WHO) categorizes it into benign, borderline, and malignant tumors based on histopathological characteristics. Malignant phyllodes tumor is an uncommon but aggressive breast malignancy and accounts for approximately 25% of all phyllodes tumors.Case Presentation: A 23-year-old female patient Gravida 0 Para 0, previously healthy, with no family history of breast or ovarian cancer was referred to our institution for managing a right breast mass increasing in size over a period of 1 month associated with reddish-brown discoloration of the skin. Breast ultrasound showed an isodense oval mass measuring approximately 16x14x12cm in the right lower outer quadrant of her breast. Core biopsy and FNA done revealed a low grade phyllodes tumor. MRI of breasts showed a huge mass of the right breast occupying all quadrants, measuring 15x14.5 cm in its greatest axis with involvement of the pectoralis major muscle, with no evidence of suspicious axillary lymphadenopathy. Distant metastatic work-up with CT scan of chest abdomen and pelvis and a PET scan did not show distant metastasis. Hence, the patient underwent right total mastectomy with a final pathology compatible with malignant phyllodes tumor. She is on regular follow up and 18 months post-surgery is still disease free.Conclusion: Management of malignant phyllodes tumor remains debatable, especially when it comes to the effect of adjuvant radiotherapy and chemotherapy. From a surgical perspective, whether phyllodes tumors should be considered as epithelial breast cancers or as soft tissue sarcoma is another debate. On the other hand, although challenging, accurate identification of phyllodes tumor initially may aid in decreased recurrence.