Introduction

Phyllodes tumor (PT) is a rare fibroepithelial breast neoplasm, accounting for <1% of all breast tumors [1, 2], with an estimated incidence of 2.1–2.6 cases per million women annually [3]. It occurs most frequently between 40 and 50 years of age and is classified as benign, borderline, or malignant according to histopathological features, including stromal cellularity, mitotic activity, nuclear atypia, tumor margins, and stromal overgrowth [4].

Malignant PTs constitute only 10%–15% of all PTs and represent an exceptionally uncommon subgroup of breast neoplasms, with an estimated incidence of 0.5–0.9 cases per million women per year [5–7]. Giant malignant PTs, generally defined as lesions larger than 10 cm, are particularly rare and pose significant diagnostic and therapeutic challenges due to their rapid growth, local aggressiveness, risk of recurrence, and potential for distant metastasis [4, 8].

These tumors typically present as a painless, rapidly enlarging breast mass with possible deformity, ulceration, or skin necrosis. Axillary involvement is uncommon due to predominantly hematogenous spread [3, 7].

Diagnosis is challenging because of its similarity to other rapidly growing breast neoplasms. Imaging studies, including ultrasound and magnetic resonance imaging, can aid in characterization; however, definitive diagnosis relies on histopathological examination [8, 9].

Complete surgical excision with negative margins is the standard treatment. Giant tumors frequently require mastectomy and reconstruction, while radiotherapy may be considered in selected cases to reduce local recurrence [6, 10].