Phyllodes tumors are rare breast neoplasms, accounting for 0.3% to 1% of all breast tumors. They are fibroepithelial lesions that can be classified as benign, borderline, or malignant [1] . The majority of phyllodes tumors are benign, representing 35% to 64% of cases [2] - [4] . Diagnostic criteria for malignant phyllodes tumors are relatively well defined by the 2019 WHO classification [5] . The aim of this study was to evaluate the contribution of core needle biopsy to preoperative diagnosis and to analyze histological concordance following surgical treatment.

In this retrospective descriptive study, the authors reviewed 24 cases of breast phyllodes tumors collected over a 5-year period (2020-2024) at the Teaching Hospital of Angre in Abidjan, complemented by a literature review. The study aimed to describe the clinical circumstances of tumor occurrence, including clinical features, duration of symptoms, surgical management, and histological findings. The 2019 WHO classification was chosen to categorize phyllodes tumors of the breast.

The sampling method was exhaustive; all women followed and operated on for phyllodes tumors of the breast at the Angré University Hospital were included in this study. A review of the scientific literature from the last 15 years was conducted. We consulted the Medline database using the PubMed search engine and also performed free-text searches using the Google Scholar search engine. The search was carried out by combining the terms (Phyllodes tumor, breast, tumorectomy) AND (Histological examination, Management).

We retrospectively reviewed 24 medical records of patients diagnosed with phyllodes tumors of the breast (PTB) over a 5-year period at the Teaching Hospital of Angre in Abidjan. The mean age at diagnosis was 31 years (range: 11 - 52 years). The average tumor size was 9 cm (range: 4 - 22 cm), with a predilection for the upper outer quadrants of the breast (45.8%).

The main clinical features are summarized in Table 1 .

Mammography was performed in 41.7% of our patients.

Fine-needle aspiration cytology, carried out in 10 patients, suggested the presence of a phyllodes breast tumor in 8 cases. Core needle biopsy showed discordance with the final histological diagnosis in 16.7% of cases (20 cases of phyllodes tumors and 4 cases initially diagnosed as fibroadenomas) ( Table 2 ).

Surgical treatment was breast-conserving in 18 patients (75%), allowing preservation of an acceptable breast volume after tumor resection with clear margins. Notably, 6 patients underwent mastectomy due to large tumor size or high histological grade, and 3 patients received breast reconstruction (mammoplasty).

No axillary surgery, chemotherapy, or radiotherapy was administered. No local recurrences were observed during a 2-year follow-up period among the 8 patients who were regularly monitored ( Figures 1-6 ).

Phyllodes tumors of the breast are rare, and most published studies in the literature are case reports or small case series [2] . In our study, the cases involved predominantly young women, with a mean age of 31 years. These tumors appear to be more frequent, larger in size, and occur at a younger age among Black patients compared to what is generally reported in the existing literature [6] . Indeed, the median age of onset described in most series ranges from 40 to 50 years [7] [8] .

Rapid growth of the breast mass led us to suspect a phyllodes tumor in the majority of cases. However, the clinical presentation of phyllodes tumors (PTs) only allows for an approximate diagnosis typically characterized by a large, lobulated mass. In our series, tumor size ranged from 4 cm to 22 cm in greatest dimension, with a mean of 9 cm, and all lesions were unilateral. In contrast, Belkacemi’s series reported tumor sizes ranging from 0.5 to 27 cm, with a mean size of 5 - 7 cm [9] .

Cutaneous changes such as erythema, striae, or inflammatory signs occur only with large or superficially located tumors [8] [10] .

The etiopathogenesis of phyllodes tumors remains unclear. However, a known risk factor has been identified: mutations in the TP53 gene, as seen in Li-Fraumeni syndrome [11] . In our cohort, patients sought medical care at variable intervals, most commonly prompted by symptoms; notably, symptom duration was less than one year in 54.1% of cases.

The diagnostic workup is well established and includes core needle biopsy followed by histological confirmation after surgical excision. In our series, histological discordance between preoperative biopsy and final pathology was observed in 16.7% of cases. This implies that in case of diagnostic doubt, surgical excision must be wide. A diagnosis of phyllodes tumour should be based on the finding of well-developed stromal fronds accompanied by increased stromal hypercellularity [10] [12] .

Imaging and cytology do not provide definitive diagnostic certainty. Computed tomography (CT) and magnetic resonance imaging (MRI) help define the local extent of disease [9] [12] . Nevertheless, Tan et al. [13] demonstrated a correlation between MRI features and histological grade based on specific criteria: tumor size, irregular margins on ultrasound, presence of non-enhancing cystic septations, and signal changes between T2-weighted and contrast-enhanced MRI sequences.

Only histological examination allows accurate grading, which is essential for optimal therapeutic decision-making [9] . Furthermore, phyllodes tumors can pose a diagnostic challenge, particularly in differentiating them from fibroadenomas or soft tissue sarcomas [2] [12] .

Histologically, phyllodes tumors are mixed fibroepithelial neoplasms, likely arising from the terminal ductolobular unit and considered stromal-derived. They are characterized by stromal hypercellularity, which typically imparts a leaf-like (“phyllodes”) architecture on gross and microscopic examination—hence the name. Although most are benign, approximately 5% are classified as malignant (Grade 3) [2] [7] - [9] [13] . Moreover, the literature reports that up to 30% of percutaneous biopsies for suspected phyllodes tumors yield false-negative results [14] [15] .

Surgical management must prioritize wide local excision with clear margins extending into healthy tissue.

Tumors are classified into three histoprognostic grades: Grade 1 (benign): No adverse histological features and negligible risk of recurrence. Grade 2 (borderline): Presence of at least one adverse histological feature and Grade 3 (malignant/sarcomatous): Presence of at least three adverse features, with a reported 25% risk of distant metastasis at 3 years [1] .

Key distinguishing features of Grade 3 tumors include a high mitotic index (>9 mitoses per 10 high-power fields), markedly increased stromal cellularity with severe atypia, and diffuse infiltrative tumor margins [16] . Grading is typically based on semi-quantitative assessment of stromal components, including nuclear pleomorphism, mitotic rate, stromal overgrowth, tumor necrosis, cellularity, and margin characteristics.

Current guidelines recommend complete tumor excision with margins of at least 1 cm [16] [17] either via wide local excision (tumorectomy) or mastectomy, without axillary lymph node dissection. The choice of surgical approach depends on patient age, tumor size, and/or histological grade following biopsy [16] .

At the Angré University Hospital, when the tumor-to-breast ratio was considered high and if the tumor was grade 3, mastectomy was recommended. We chose a size of 20 cm as a reference for mastectomy. Despite advances in oncoplastic breast-conserving techniques, very large phyllodes tumours (PT) may still be recommended for mastectomy [18] .

In our series, this principle was strictly adhered to: six patients underwent simple mastectomy without lymph node dissection, while those who had tumorectomy achieved clear resection margins (minimum 10 mm of healthy tissue) [19] . However, Onkendi et al. [20] , in a study of 67 borderline and malignant phyllodes tumours from the Mayo Clinic, found that the extent of surgical excision had no impact on disease-free survival.

Prognosis is primarily determined by the risk of local recurrence and distant metastasis, warranting regular clinical and radiological follow-up for at least 2 years [21] [22] . However, implementing such surveillance remains challenging in sub-Saharan African settings due to limited resources and infrastructure. Our study being retrospective, this resulted in a high rate of patients lost to follow-up. In sub-Saharan Africa, once patients are informed of the benign diagnosis, they no longer see any benefit in long-term follow-up. Overall, recurrence rates in the literature are 10% - 17%, 14% - 25% and 23% - 30% for benign, borderline and malignant phyllodes tumours, respectively. However, it is accepted that adverse events are, in general, rare for all forms of phyllodes tumours when they are subjected to complete local excision [16] .

Phyllodes tumors are very rare breast neoplasms, with diagnosis typically suggested by core needle biopsy. Prognosis is ultimately determined by histopathological findings. In cases of presumed benign disease, breast-conserving surgery remains the standard of care, provided that wide excision with clear margins is achieved, followed by rigorous clinical and radiological surveillance. Our observations highlight the real-world challenges in ensuring adequate postoperative follow-up after conservative surgery, particularly in resource-limited settings. Given the heterogeneity of phyllodes tumors ranging from benign to frankly malignant it is essential to develop tailored, context-sensitive management guidelines that account for this spectrum of disease behavior. To reduce diagnostic discrepancies in breast phyllodes tumors, experienced pathologists should collaborate to ensure reliable results. For patients lost to follow-up, oncologists from the CNRAO (National Radiotherapy Center) should be involved to ensure optimal patient monitoring.