Giant Benign Phyllodes Tumor Presenting with Skin Ulceration: A Case Report and Review of the Literature

Phyllodes tumors of the breast are rare fibroepithelial neoplasms accounting for 0.3%-1.0% of all primary breast tumors. They are classified into benign, borderline, and malignant subtypes, with borderline and malignant tumors associated with an increased risk of local recurrence and distant metastasis. Giant phyllodes tumors, defined as tumors larger than 10 cm in diameter, are uncommon, and reports of tumors exceeding 20 cm are extremely rare. We report a case of a rapidly growing giant benign phyllodes tumor with skin ulceration, along with a review of the relevant literature.

A 48-year-old Asian woman presented with rapid enlargement of the left breast and active bleeding from an ulcerated mass. Clinical findings and imaging studies revealed a well-circumscribed giant tumor measuring 24 cm that occupied the entire left breast, without evidence of distant metastasis. Core needle biopsy suggested a fibroepithelial tumor, and a benign phyllodes tumor was most strongly considered. A left mastectomy was performed. Skin grafting had been considered preoperatively, as the skin defect would be large. However, as sufficient skin flaps were obtained intraoperatively, due to the skin being stretched by the tumor, only mastectomy was done without a reconstructive procedure. Histopathological examination confirmed a benign phyllodes tumor with negative surgical margins. The postoperative course was uneventful.

We experienced a rare case of a giant breast tumor and tumor resection. Although rapid breast tumor growth and skin breakdown suggested malignancy, the pathological diagnosis was a benign phyllodes tumor. This highlights the importance of considering phyllodes tumors in the differential diagnosis of rapidly enlarging breast masses and the need for timely surgical intervention. This case is particularly noteworthy because it demonstrates an unusual combination of clinical features-giant tumor size, rapid growth, and skin ulceration-that are generally associated with malignant disease, despite the final diagnosis being benign.