Clinicopathology and treatment of a giant malignant phyllodes tumor of the breast: A case report and literature review

INTRODUCTION: Phyllodes tumors (PTs) of the breast are extremely rare accounting for less than 1% of all breast tumors globally. Case records at the Trinidad and Tobago Cancer Registry show that only 0.003% of the reported breast cancer cases between 1995 and 2009 were PTs. PRESENTATION OF THE CASE: We report a 45-year-old woman who presented with swelling of the left breast. Ultrasound, mammogram and computed tomography imaging confirmed the presence of a mass in the right upper inner quadrant of the left breast. A biopsy revealed features supportive of a benign phyllodes tumor. A wide local excision was performed with the removal of a 19 × 11 × 10 cm mass. Histopathological analysis revealed features consistent with malignant phyllodes tumor. A complete mastectomy of the left breast was subsequently performed. Follow up over a 5-year period did not reveal any evidence of local recurrence or residual disease. To the best of our knowledge, this is the first case report of a malignant PT from the Caribbean and Latin America. DISCUSSION: Phyllodes tumors are classified as benign, borderline, or malignant based on histologic features including presence of a clear margin, cellularity, stromal overgrowth, tumor necrosis and mitotic index. The clinical challenge is to assess the risk of local tumor and metastatic recurrence in the context of fluid classifications. CONCLUSION: Our case management approach shows that for patients with malignant PT, a thorough preoperative workup regimen followed by appropriate surgical intervention can result in a desirable prognosis.