Malignant Phyllodes Tumor in Adolescent Females: A Report of Three Cases and Review of the Literature.

Malignant phyllodes tumors (MPTs) are quite a rare type of mesenchymal breast cancer that can mimic benign lesions such as fibroadenomas histologically and radiologically. They account for less than 1% of all breast cancers, and they usually occur commonly in younger and middle-aged women. We report three cases of MPT with ages ranging between 15 and 20 years from the Eastern region of Uganda that were obtained consecutively at our institution for the period of 3 years (from 2023 to 2025). Case 1 was a 15-year-old female with 2 months history of a left breast mass that was painful, rapidly growing, and associated with ulceration; it was confirmed histologically to be MPT and was treated successfully with ifosfamide 390 mg, doxorubicin 48 mg, and dexamethasone 8 mg. Case 2 was a 19-year-old female with 6-month history of a right breast mass that was associated with pain and tenderness, and the mass was confirmed histologically to be MPT though she died before the initiation of treatment. Case 3 was a 20-year-old female with 3-month history of a left breast mass that was associated with intermittent pains. She also had a positive family history of breast cancer. Her mass in the breast was confirmed histologically to be MPT and she was also treated with ifosfamide 390 mg, doxorubicin 48 mg, and dexamethasone 8 mg. All three cases tested positive for vimentin, but case 2 also showed focally positive SMA, but all of them were triple negative with Ki67 expression ranging from 20% to 35%. MPTs are rare and are more likely to recur, and they tend to have rapid growth and metastasis. Timely and proper management of patients with MPT helps to prevent possibilities of metastasis and improve the prognosis of the patients.