Breast tumor with giant phyllodes: a case report

Introduction

Breast Phyllodes tumor is a rare fibroepithelial neoplasm, accounting for approximately 0.3‒1.0% of all breast neoplasms and typically measuring approximately 4 cm in diameter (1). Giant phyllodes tumor, defined as a lesion with a maximum diameter exceeding 10 cm, is even more rarer (2). These tumors typically grow rapidly and may be associated with skin ulcerations or local compressive symptoms. Intraoperatively, massive hemorrhage can obscure the surgical field, increase the risk of complications, and hinder complete resection. Preoperative diagnosis is challenging as imaging features often overlap with those of fibroadenoma and other mesenchymal lesions. Although complete surgical excision is the standard treatment, there is currently no standardized strategy for the management of intraoperative bleeding. Herein, we present a case of a giant phyllodes breast tumor in a 36-year-old woman. A two-step hemostatic approach is detailed, along with the diagnostic and therapeutic rationale, to inform the management of similar cases in the future. We present this article in accordance with the CARE reporting checklist (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0137/rc).

Case presentation

A 36-year-old woman was admitted to the Department of Breast Surgery, Third Xiangya Hospital Affiliated to Central South University on October 8, 2025. Her chief complaint was a right breast mass that had been present for 2 years. The patient had no significant medical, personal, or reproductive issues apart from a history of type 2 diabetes mellitus. Her menstrual cycles were regular. There was no family history of similar conditions. Physical examination revealed a soft, irregular mass measuring 25 cm × 17 cm in the right breast. The lesion demonstrated ill-defined borders, poor mobility and was not tender (Figure 1). There was no enlargement of the bilateral axillary and supraclavicular fossa lymph nodes.

Figure 1 The mass in the right breast of the patient on admission (size approximately 25 cm × 17 cm).

Mammography indicated a giant right breast mass with calcifications, measuring approximately 178 mm × 113 mm on maximum cross-section [Breast Imaging Reporting and Data System (BI-RADS) 4C]. Breast ultrasound revealed multiple giant hypoechoic masses in the right breast, accompanied by numerous anechoic areas and calcifications, the pathological characteristics demonstrated breast sarcoma or similar malignancy (BI-RADS 4C). Computed tomography (CT) showed a large space-occupying lesion in the right breast, measuring approximately 251 mm × 184 mm × 176 mm in maximum cross-section (BI-RADS 4), suggestive of a neoplastic lesion with high possibility of being of mesenchymal origin, while phyllodes tumor, fibroadenoma, and breast cancer could not be ruled out (Figure 2), and an additional magnetic resonance imaging (MRI) examination was advised. Bilateral breast MRI was not feasible due to the large size of the mass. For further clarification of the lesion type, the patient underwent core needle biopsy on October 10, 2025. The pathological findings suggested a mesenchymal tumor-like or neoplastic lesion, although a phyllodes tumor or another entity could not be excluded. Immunohistochemical results were negative for cytokeratin (CK), CK7, CK5/6, p63, and HCK, but positive for cytoplasmic β-catenin and Ki-67 (2%). These findings led to a preliminary diagnosis of “right breast phyllodes tumor” after multidisciplinary team (MDT) consultation, which recommended interventional diagnosis and treatment to assess the need for superficial vascular embolization, aiming to reduce intraoperative bleeding. The patient underwent embolization combined with angiography of the right lateral thoracic artery, right subscapular artery, and right internal thoracic arteries on October 18, 2025. Post-embolization re-evaluation showed markedly reduced tumor staining, with no obvious signs of embolization in the main trunks and branches of the main feeding arteries. After completion of preoperative preparations, the patient underwent “giant right breast mass resection” under general anesthesia on October 20, 2025. Intraoperative frozen-section pathology confirmed a phyllodes tumor of the right breast. To further minimize intraoperative bleeding, interrupted suture ligation of subcutaneous blood vessels was performed around the mass prior to resection, and the surrounding sutures were removed after complete excision of the mass. The resected phyllodes tumor weighed 4.42 kg (Figure 3). Pathological examination of the mass indicated a giant phyllodes tumor with extensive hemorrhagic degeneration and infarction, as well as focal brisk stromal cellular proliferation with atypia and focal overgrowth; borderline changes could not be excluded. As the tumor carries a risk of recurrence, regular follow-up was recommended. The patient’s postoperative recovery was uneventful (Figure 4). At the 5-month postoperative follow-up, the patient had recovered well with no evidence of recurrence and was satisfied with the treatment outcome (Figure 5).

Figure 2 CT images showing the large space-occupying lesion in the right breast. CT, computed tomography.

Figure 3 Tumor after complete resection (weight, 4.42 kg).

Figure 4 Postoperative pathological sections of the right breast. Giant phyllodes tumor with extensive hemorrhagic degeneration and infarction; focal brisk stromal cellular proliferation with atypia and focal overgrowth; borderline change could not be excluded.

Figure 5 Postoperative healing of the wound. (A) Wound healing at 1 week postoperatively; (B) healing at the 5-month follow-up after surgery.

Ethical consideration

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

Phyllodes tumors occur predominantly in middle-aged women aged 40–50 years (3), and account for approximately 0.3–1% of all breast tumors (4). Phyllodes tumors are classified into three subtypes based on histopathological features, such as stromal cellular density, mitotic activity, and stromal overgrowth: benign, borderline, and malignant (5). Histopathologically, phyllodes tumors exhibit a biphasic structure consisting of epithelial components and a cell-dense stroma, typically arranged in a leaf-like architecture.

The histological grading of phyllodes tumors follows a continuous spectrum from benign to malignant. Benign phyllodes tumors are characterized by well-defined (“pushing”) borders, mild stromal cellularity, minimal atypia, fewer than five mitotic figures per 10 high-power fields (HPFs), and no stromal overgrowth or malignant components. In contrast, borderline phyllodes tumors exhibit focally permeative or well-defined borders, moderate stromal cellularity, mild to moderate atypia, and five to nine mitotic figures per 10 HPFs, also with no malignant components. Malignant phyllodes tumors, at the other extreme, show permeative margins, pronounced stromal cellularity and atypia, stromal overgrowth, and at least 10 mitotic figures per 10 HPFs. The mitotic count, cellular atypia, and stromal cellularity increase stepwise with tumor grade across this grading continuum, while the presence of stromal overgrowth and permeative margins further distinguishes malignant from lower-grade tumors (6).

The local recurrence of phyllodes tumors is influenced by several histological factors, including mitotic activity, border type, stromal cellularity and atypia, stromal overgrowth, necrosis, and fibroproliferation. However, the reported recurrence rates vary considerably across studies. The recurrence rates for benign, borderline, and malignant phyllodes tumors range from 10‒17%, 14‒25%, and 23‒30%, respectively (7). Interestingly, despite the overall stepwise increase in local relapse, borderline tumors rarely metastasize or cause disease-related death. Additionally, Asian populations appear to have higher recurrence rates than non-Asian cohorts (8), suggesting potential ethnic or biological differences in tumor behavior.

Phyllodes tumors are defined as “giant” when their maximum diameter exceeds 10 cm (2). Clinically, early-stage phyllodes tumors typically present as unilateral, mobile, and painless masses and are often overlooked due to their slow growth. However, in some cases, the tumor may enlarge rapidly with an exponential increase in volume within weeks to months, resulting in many of these being initially misdiagnosed as fibroadenomas or mastitis. Expansion of the tumor may be associated with skin tightness, ulceration, necrosis, and malodorous discharge, while local compression can also lead to chest wall pain, dyspnea, and even involve the pectoralis major muscle.

Surgical resection is the cornerstone of treatment for giant phyllodes tumors, while preoperative core needle biopsy can preliminarily confirm the pathological type of the tumor, providing crucial evidence for the selection of surgical approaches. Specifically, complete resection with wide margins is the main therapeutic principle for benign and borderline Phyllodes tumors, which is consistent with the guidelines of the National Comprehensive Cancer Network (NCCN) (9). For malignant Phyllodes tumors, chemotherapy and radiotherapy have no significant efficacy, but radical surgical resection remains the primary treatment. The main challenge in recoverin GPTs is intraoperative massive hemorrhage.

To address this issue, we adopted a “two-step” evidence-based hemostatic strategy. First, interventional radiologists performed preoperative arterial embolization of the main arteries feeding the right breast (lateral thoracic, subscapular, and internal thoracic arteries). Studies (10-12) have shown that preoperative endovascular embolization can reduce intraoperative blood loss. Post-embolization imaging showed marked reductions in tumor staining, confirming that the main blood supply to the tumor had been successfully occluded. Second, intraoperative circumferential suture ligation of the tumor was performed to block the superficial subcutaneous vascular network, including the capillary plexuses and small arteriovenous branches, through physical compression, thereby reducing blood perfusion in the incision area at the source. The synergistic effects of these two measures are reflected in two aspects: first, they provided a clear surgical field enabling precise dissection, which is critical for protecting normal tissues and performing random flap plasty, and second, they reduced the likelihood of hemorrhage-related complications, such as hematoma and subcutaneous ecchymosis. This combined hemostatic strategy offers a safe and feasible treatment approach for similar cases.

Conclusions

Giant phyllodes tumors of the breast are rare fibroepithelial neoplasms characterized by their large size and extensive vascularity. Massive intraoperative hemorrhage is a major surgical challenge. In this case, the giant phyllodes tumor was managed using a “two-step” hemostatic strategy involving preoperative arterial embolization and intraoperative circumferential suture ligation. This approach effectively reduced intraoperative bleeding, facilitating an uneventful postoperative recovery free of hemorrhagic complications and confirming the safety and feasibility of the strategy. In accordance with the NCCN guidelines, this approach addresses the core therapeutic dilemma presented by giant phyllodes tumors, and the findings provide practical evidence for the management of hypervascular, large-volume breast tumors.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0137/rc

Peer Review File: Available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0137/prf

Funding: This work was supported by the China Zhongguancun Precision Medicine Science and Technology Foundation (No. ZGC-YXKY-117X).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://gs.amegroups.com/article/view/10.21037/gs-2026-1-0137/coif). B.D. reports that this work was supported by the China Zhongguancun Precision Medicine Science and Technology Foundation (No. ZGC-YXKY-117X). The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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