Diagnostic Maze: Malignant Phyllodes Tumor Mimicking Metaplastic Breast Carcinoma.

Phyllodes tumors (PTs) are uncommon breast tumors. They represent a spectrum of benign to malignant neoplasms. These erratic tumors have traits ranging from fibroadenomas on one end of the spectrum to sarcomas on the other end. The presentation of PT is variable, thus posing a diagnostic difficulty. Malignant PTs are often associated with recurrence, poor prognosis, and adverse disease outcomes. The recent genetic studies produced by genome sequencing offer information about the molecular pathophysiology of PT, aid in enhancing diagnostic precision, and suggest possible therapeutic targets in cases of malignant PT. Planning a treatment modality and prognostication requires meticulous histopathological sampling, as it relies on a correct histopathological diagnosis. There are no definitive guidelines for surgical management and targeted therapy for malignant PTs due to the rarity of these cases and very little available literature on these topics. Here in this article, we address a malignant PT in a 74-year-old female that presented as a breast mass mimicking metaplastic breast carcinoma histologically. This article also illuminates how immunohistochemistry plays a vital role in the diagnosis of this tumor.

Recurrent and transformation of borderline to malignant phyllodes tumour with osteoid differentiation: a case report and literature review.

Phyllodes tumours or cystosarcoma phyllodes are fibroepithelial tumours of the breast and represent 1% of breast tumours. A 20-year-old nullipara presented with an enlarging left breast mass over 6 months. Although widely excised, it was reported to be a 12 × 10 × 5.5-cm borderline phyllodes tumour with involvement of the superior and inferior margins. Seven months later, she presented with a new ipsilateral breast lump measuring 8.5 × 7.5 × 4.6 cm. She underwent a left mastectomy, a three-rib resection with titanic rods for the thoracic cage reconstruction, and a latissimus dorsi flap wound closure. Histopathology revealed a high-grade malignant phyllodes tumour with features of osteoid differentiation with the nearest deep margin measuring 3 mm. She developed metastasis to the ipsilateral axillary lymph nodes and contralateral lung 2 months postoperatively. She was given palliative radiotherapy 60 Gy in 30 fractions to the left axilla. She developed sudden lower-limb weakness due to spinal metastases. The symptoms resolved with radiotherapy to the thoracic spine (T4-T8). As the lesion continued to grow rapidly from the anterior chest wall encircling towards the back, it was deemed unresectable. She was given palliative chemotherapy (doxorubicin six cycles, followed by ifosfamide one cycle) but had disease progression. She passed away 3 months later. The mainstay of treatment for phyllodes tumour is excision with a minimal margin of 1 cm. Although margins were involved after the first surgery, she was followed up as the pathology was a borderline phyllodes. When the lump recurred and had transformed, despite extensive surgery, it returned shortly and progressed. A borderline phyllodes should be excised to obtain a minimal margin of 1 cm, even if it means performing a mastectomy, to minimise recurrence. A recurrence may undergo malignant transformation which is largely chemotherapy and radiotherapy resistant. This will result in a poor outcome and decreased survival.

Nipple-sparing mastectomy and immediate breast reconstruction by prepectoral implant for the management of giant phyllodes tumors: A case series.

Phyllodes tumor is an uncommon breast neoplasm that is present in variable sizes. Giant phyllodes are those larger than 10 cm in diameter. Clinically, giant phyllodes tumors present as a visible, rapidly growing mass distorting the breast contour. Such tumors with large size and rapid growth rate suggest a phyllode diagnosis of fibroadenoma. Planning a standard treatment strategy for these tumors is quite challenging. While adequate surgical excision with tumor-free resection margins is the standard of care for most giant phyllodes cases, borderline and malignant giant phyllodes tumors might require wider resections given their high recurrence rates. Some authors described total mastectomy as the treatment option for giant borderline and malignant phyllodes to obtain wide, clear margins. Between March 2022 and September 2023, our surgical oncology department presented and operated on three cases of giant phyllodes. They underwent a nipple-sparing mastectomy and immediate breast reconstruction using pre-pectoral silicone implants. We think that with such a procedure, we can benefit from the wide, safe margins of mastectomy that have been proven to decrease local recurrence rates while considering the aesthetic outcome.

Massive malignant phyllodes tumor accompanied by anemia and ulceration in the breast: A case report.

Large malignant breast phyllodes tumors are uncommon in clinical settings. Here, we report such a case to provide a reference for clinical work. A 48-year-old woman identified a lump in her right breast, which eventually grew up to 25 cm × 10 cm and began to rapidly bleed and ulcerate within 3 months. The patient had visible signs of anemia and significant emaciation as a result of the tumor's wasting effect and the protracted course of the disease. The patient underwent a modified radical mastectomy on the right breast. The pathology results obtained after surgery revealed a malignant phyllodes tumor. No adjuvant therapy, such as chemotherapy or radiation, was administered. The patient had no symptoms of tumor recurrence and complications from the surgery after a follow-up of 9 months.

De-escalating indications for excision when breast core needle biopsy returns fibroepithelial lesion-not further characterized.

PURPOSE: Surgical excision is often performed to exclude phyllodes tumor (PT) when Core Needle Biopsy (CNB) of the breast returns fibroepithelial lesion-not further characterized (FEL-NFC). If imaging or CNB pathology features can be identified that predict a very low probability of borderline/malignant PT, thousands of women could be spared the expense and morbidity of surgical excisions. METHODS: This retrospective cohort study includes 180 FEL-NFC from 164 patients who underwent surgical excisional biopsy. RESULTS: The upgrade rate from FEL-NFC to benign PT was 15%, and to borderline/malignant PT 7%. Imaging features predicting upgrade to borderline/malignant PT included greater size (p = 0.0002) and heterogeneous echo pattern on sonography (p = 0.117). Histologic features of CNB predicting upgrade to borderline/malignant PT included "pathologist favors PT" (p = 0.012), mitoses (p = 0.014), stromal overgrowth (p = 0.006), increased cellularity (p = 0.0001) and leaf-like architecture (p = 0.077). A three-component score including size > 4.5 cm (Size), heterogeneous echo pattern on sonography (Heterogeneity), and stromal overgrowth on CNB (Overgrowth) maximized the product of sensitivity x specificity for the prediction of borderline/malignant PT. When the SHO score was 0 (72% of FEL-NFC) the probability of borderline/malignant PT on excision was only 1%. CONCLUSION: The combination of size ≤ 4.5 cm, homogeneous echo pattern, and absence of stromal overgrowth is highly predictive of a benign excision potentially sparing most patients diagnosed with FEL-NFC the expense and morbidity of a surgical excision.

Clinical presentation and radiologic imaging findings of phyllodes tumors: benign and borderline/malignant phyllodes tumors.

Background: Phyllodes tumor is a rare fibroepithelial neoplasm of the breast, which is classified histologically as benign, borderline, or malignant. Accurate preoperative diagnosis allows the correct surgical planning and reoperation avoidance. Objective: To describe the clinical presentation and radiologic features of phyllodes tumors and differentiate between benign and non-benign (borderline and malignant) groups. Methods: A retrospective study of 57 patients with a diagnosis of phyllodes tumor who had preoperative imaging (mammography, ultrasound, or CT chest) and histological confirmation. The data was collected from 1 June 2011 to 30 September 2021. The imaging features of the phyllodes tumors were described according to the 5th edition of the ACR BI-RADS lexicon. For comparing between two groups, the student t-test, Wilcoxon rank sum test, Chi-square test, and Fisher's exact test were used for statistical analyses. The logistic regression analysis was calculated for non-benign phyllodes tumor prediction. Results: From 57 patients, the pathologic results were benign for 43 cases and non-benign phyllodes tumors for 14 cases. There was no differentiation of mammographic and CT features between benign and non-benign groups. Non-benign phyllodes tumors had the statistical significance of menopausal status, entire breast involvement, tumor size larger than 10 cm, and heterogeneous echo on univariable analysis. After multivariable analysis, menopausal status (odd ratios=13.79, p=0.04) and presence of vessels in the rim (odd ratios=16.51, p=0.019) or absent vascularity (odd ratios=8.45, p=0.047) on doppler ultrasound were significantly increased possibility of non-benign phyllodes tumor. Conclusions: Menopausal status and presence of vessels in the rim or absent vascularity on Doppler ultrasound were important predictors for the diagnosis of non-benign phyllodes tumor.

Malignant phyllodes tumor with EGFR variant III mutation: A rare case report with immunohistochemical and genomic studies.

A female in her 60's presented with a left-sided breast mass. A core needle biopsy specimen showed diffuse proliferation of a round cell tumor, which was positive for vimentin, NKX2.2, BCOR, and focal CD99 on immunohistochemistry (IHC). No fusion genes of the Ewing family sarcomas were detected. With a tentative diagnosis of primary breast sarcoma (PBS), total mastectomy was performed after chemotherapy. The resected tissues showed proliferation of round or spindle-shaped tumor cells with a high nuclear-to-cytoplasmic ratio, exhibiting solid and fascicular arrangements but no epithelial component or organoid pattern. While IHC indicated no particular histological diagnosis, genomic examination revealed gene alterations in MED12 p.G44D, MLL2 (KMT2D) p.T1496fs*27, and EGFR variant III (vIII). Moreover, a retrospective IHC study showed overexpression of EGFRvIII. A malignant phyllodes tumor (PT) with extensive sarcomatous overgrowth was indicated as an integrative diagnosis. This is a rare case of a malignant PT harboring EGFRvIII. The present case provides an importance of accurate diagnosis and genomic analysis of rare breast tumors, as malignant PT and PBS are different in its treatment strategy and prognosis.

Giant Borderline Phyllodes Tumor Fungating Through the Skin as Fleshy Polypoid Outgrowths.

We present the case of a 52-year-old female with a giant phyllodes tumor (GPT), which was fungating through the skin that showed fleshy polypoid outgrowths. Histological analysis revealed stromal atypia, mitotic activity, and stromal overgrowth; however, the tumor border was well-defined, and malignant heterologous elements were not observed. Therefore, as some but not all malignant histological characteristics were present, we diagnosed the patient with borderline GPT. In cases of phyllodes tumor (PT) with the unique gross findings of fungation through the skin as fleshy polypoid outgrowths, caution is required for the subsequent course because even if the PT is graded as benign histologically, a malignant process can occur. Pathologists should note that the sampling of the collection site and the ambiguity of the histological grading of PT may affect the final diagnosis of GPT. It is also important to perform surgery with adequate preservation of the resected margins to control recurrence for patients with GPT.

Unusual Metastatic Sites in Malignant Phyllodes Tumor Detected on FDG PET/CT.

Phyllodes tumor is a rare fibroepithelial neoplasm of the breast. This tumor tends to spread by hematogenous route, with common metastatic sites in the lungs, bones, and liver. Metastases to the pleura, stomach, pancreas, kidneys, and adrenal gland are rare. We present a case of a 52-year-old lady with malignant phyllodes tumor of breast undergone local tumor resection, followed by solitary lung metastasis with lobectomy, and subsequently diagnosed of multiple new metastatic sites in pleura, stomach, pancreas, kidneys, adrenal gland, and bone detected on 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography within 2 years.

Fibroepithelial Neoplasm with Hybrid Features of Benign Phyllodes Tumor, Juvenile Papillomatosis, and Juvenile Fibroadenoma: A Case Report.

Phyllodes tumor is an uncommon breast fibroepithelial neoplasm mainly found in middle-aged patients, presenting a morphologic continuum from benign to malignant. Juvenile papillomatosis represents a rare benign proliferative breast tumor primarily affecting young individuals and carries a potential elevated risk of subsequent breast cancer development. Juvenile fibroadenoma is a well-circumscribed biphasic neoplasm that often occurs in adolescent girls, characterized by a pericanalicular growth pattern with usual-type epithelial hyperplasia and gynaecomastia-like micropapillary proliferation. Herein, we present an unusual example of a 26-year-old woman with a left breast outer lower quadrant palpable mass. Ultrasonography identified a 5.9 cm lobulated hypoechoic solid mass with scattered small cysts. The preoperative biopsy initially diagnosed a fibroepithelial lesion, considering giant cellular fibroadenoma and phyllodes tumor in the differential. Subsequent complete excision revealed areas of benign phyllodes tumor features closely admixed with distinctive elements such as prominent multiple cysts exhibiting apocrine and papillary apocrine metaplasia, duct papillomatosis, and duct stasis characteristic of juvenile papillomatosis, and hyperplastic ductal epithelium with micropapillary projections demonstrating a pericanalicular growth pattern indicative of juvenile fibroadenoma. The diagnosis was conclusively established as a fibroepithelial lesion with combined features of benign phyllodes tumor, juvenile papillomatosis, and juvenile fibroadenoma. Further investigation uncovered a family history of breast cancer. Molecular analysis revealed a pattern of unique and overlapping mutations within these distinct histopathological areas. This unusual presentation with hybrid features within a single tumor is described for the first time in the literature along with the molecular signature of the individual components.

A Unique Presentation of a Giant Fibroadenoma in a Perimenopausal Female.

Giant fibroadenomas are common in young females and are rarely reported in perimenopausal or menopausal females. These fibroadenomas are observed as single, mobile, small to large, with distinct boundaries. These tumors are hyperplastic and characterized by their aberrant growth in both the epidermal and mesenchymal layers, which can be accompanied by pain in some instances. These tumors have similar clinical resemblances to other epithelial and stromal tumors, such as phyllodes tumors, except for the level of disease severity and malignancy. Treatment of giant fibroadenomas includes surgical resection. Surgical excision is done by complete excision of the fibroadenoma, with the rest of the breast tissue and the nipple-areolar complex preserved. Timely diagnosis can be helpful in the prevention of adverse outcomes. This is a case of a 40-year-old female who presented with a lump in her right breast, for which she underwent a wide local excision. On histopathology, it was found to be a giant fibroadenoma. Her postoperative recovery was uneventful.

Recurrent giant phyllodes tumor of the breast: a case report.

Background: Phyllodes tumors (PTs) account for 0.3-1.0% of all breast tumors and often occur in women aged 35 to 55. They are similar to giant fibroadenomas. PTs are famous for local recurrence. No more than 10% of PTs grow larger than 10 cm. The National Comprehensive Cancer Network (NCCN) guidelines recommend extensive resection with a margin of ≥1 cm for PTs, which is much larger than that required for breast cancer. Positive resection margin is associated with recurrence. However, little is known about whether all subtypes really require radical tumor negative resection margins. Case Description: We report on a 49-year-old woman with a giant borderline PT in her left breast. The tumor was greater than 10.5 cm × 7.0 cm. She had a bilateral benign PT excision in January 2014 and a left benign PT excision in December 2018. A chest computerized tomography (CT) scan and abdomen ultrasound did not reveal distant metastasis. Therefore, left breast mastectomy was performed. Wound healing was satisfactory. Pathological and immunohistochemistry findings showed a borderline PT. Conclusions: As the rare tumor of the breast, PTs pose a great challenge for surgeons. The initial evaluation of PTs relies on a triple evaluation of clinical, radiological, and histological examination. Local recurrence of PTs is more common than distant metastasis. The histology of recurrent tumors is usually identical to that of the primary tumor, or has a tendency to malignancy. Although most surgeons are uncomfortable with PTs with a positive margin, it is reasonable to adopt a "watchful waiting" strategy for benign PTs. The current recommendation that PTs should be extensively resected regardless of tumor size might be revised.

Effect of adjuvant radiotherapy on overall survival and breast cancer-specific survival of patients with malignant phyllodes tumor of the breast in different age groups: a retrospective observational study based on SEER.

PURPOSE: Malignant phyllodes tumor of the breast (MPTB) is a rare type of breast cancer, with an incidence of less than 1%. The value of adjuvant radiotherapy (RT) for MPTB has been controversial. The aim of the study was to explore the effect of radiotherapy on the long-term survival of female patients with MPTB at different ages. METHODS: Female MPTB patients were selected from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2020. A Kaplan-Meier survival analysis was conducted to investigate the value of RT for the long-term survival of MPTB patients in different age groups. Additionally, univariate and multivariate Cox regression analyses were performed for overall survival (OS) and breast cancer-specific survival (BCSS) of MPTB patients. Furthermore, propensity score matching (PSM) was also performed to balance the differences in baseline characteristics. RESULTS: 2261 MPTB patients were included in this study, including 455 patients (20.12%) with RT and 1806 patients (79.88%) without RT. These patients were divided into four cohorts based on their ages: 18-45, 46-55, 56-65, and 65-80. Before adjustment, there was a statistically significant difference in long-term survival between RT-treated and non-RT-treated patients in the younger age groups (age group of 18-45 years: OS P = 0.019, BCSS P = 0.016; age group of 46-55 years: OS P < 0.001, BCSS P < 0.001). After PSM, no difference was found in long-term survival of patients in both younger and older groups regardless of whether they received RT (age group of 18-45 years: OS P = 0.473, BCSS P = 0.750; age group of 46-55 years: OS P = 0.380, BCSS P = 0.816, age group of 56-65 years: OS P = 0.484, BCSS P = 0.290; age group of 66-80 years: OS P = 0.997, BCSS P = 0.763). In multivariate COX regression analysis, RT did not affect long-term survival in patients with MPTB. CONCLUSION: There is no evidence that long-term survival of MPTB patients in specific age groups can benefit from RT.

A Case Series of Round Block Techniques for Large, Recurrent, and Multicentric Benign Breast Diseases.

Benign breast diseases are a common presentation in the breast clinic outpatient department. These diseases, including giant fibroadenoma, multiple fibroadenoma in different quadrants, and large or recurrent phyllodes tumors, pose challenges in surgical management. We present a case series of 16 patients aged 19 to 63 years (average age, 41.5 years) who presented with breast lumps and underwent surgery using the round block technique for benign breast diseases at our institute between November 2019 and March 2024. Prior to surgery, all patients had clinical, radiological, and pathological assessments. Age, duration of lump, and detailed menstrual, obstetric, and family history of each patient were recorded. Eight (50%) of the patients had phyllodes tumor, four (31.25%) had fibroadenoma, three (18.75%) had both fibroadenoma and phyllodes tumor, and one (6.25%) had adenolipoma. The average size of tumors was 7.5 cm in our study. During postsurgical follow-up, none of the patients had nipple areola necrosis, and they reported that nipple sensation was acceptable. A mastectomy was avoided in all circumstances. Good cosmetic outcomes and clear margin status are achievable using the round block technique.

Giant Borderline Phyllodes Tumor of the Breast: A Case Report.

Borderline phyllodes tumor is a rare and benign form of breast cancer with malignant potential. According to the World Health Organization (WHO), phyllodes tumor is classified into three categories: benign, borderline, and malignant. The treatment of phyllodes tumor is wide focal excision combined with radiotherapy and chemotherapy in certain cases. Herein, we report a 47-year-old female who presented with a giant borderline mass approximately 19.5 x 16.9 x 9.3 cm in size. From medical history, we noticed that the mass begun to develop during puberty. Wide focal excision of the tumor and immediate implant-based reconstruction with free nipple graft was performed, with the tumor specimen measuring 16.5 x 14.2 x 8.7 cm. Histological examination reported a borderline phyllodes tumor, and in this case, the patient did not undergo adjuvant treatment.

Vacuum-assisted excision: a safe minimally invasive option for benign phyllodes tumor diagnosis and treatment-a systematic review and meta-analysis.

Synopsis: This is a systematic review and meta-analysis comparing surgical excision with percutaneous ultrasound-guided vacuum-assisted excision (US-VAE) for the treatment of benign phyllodes tumor (PT) using local recurrence (LR) as the endpoint. Objective: To determine the frequency of local recurrence (LR) of benign phyllodes tumor (PT) after ultrasound-guided vacuum-assisted excision (US-VAE) compared to the frequency of LR after surgical excision. Method: A systematic review and meta-analysis [following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standard] was conducted by comparing LR in women older than 18 years treated for benign PT by US-VAE compared with local surgical excision with at least 12 months of follow-up. Studies were retrieved from PubMed, Scopus, Web of Science, and Embase. The pooled effect measure used was the odds ratio (OR) of recurrence. Results: Five comparative prospective or retrospective observational studies published between January 1, 1992, and January 10, 2022, comparing surgical excision with percutaneous US-VAE for LR of benign PT met the selection criteria. Four were retrospective observational cohorts, and one was a prospective observational cohort. A total of 778 women were followed up. Of them, 439 (56.4%) underwent local surgical excision, and 339 (43.6%) patients had US-VAE. The median age of patients in the five studies ranged from 33.7 to 39 years; the median size ranged from 1.5 cm to 3.0 cm, and the median follow-up ranged from 12 months to 46.6 months. The needle gauge ranged from 7G to 11G. LR rates were not statically significant between US-VAE and surgical excision (41 of 339 versus 34 of 439; OR 1.3; p = 0.29). Conclusion: This meta-analysis suggests that using US-VAE for the removal of benign PT does not increase local regional recurrence and is a safe minimally invasive therapeutic option. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42022309782.

Optimizing aesthetic results in Asian women with giant phyllodes tumors over 10 cm: the periareolar mastopexy approach.

Giant phyllodes tumors, typically exceeding 10 cm in size, are neoplastic lesions with malignant potential. Surgical excision in small-breasted Asian women presents unique challenges where expected poor aesthetic outcomes may delay timely medical intervention. The periareolar mastopexy technique offers a comprehensive solution, enabling complete tumor removal alongside mastopexy to achieve optimal breast contouring. This approach consistently delivers favorable aesthetic outcomes, enhancing symmetry and contour. Additionally, the periareolar approach minimizes visible scarring, thereby enhancing patient satisfaction with the cosmetic outcome. Herein, we present a case report of Asian women with giant phyllodes tumors exceeding 10 cm, successfully managed using the periareolar mastopexy technique, emphasizing the importance of optimizing aesthetic outcomes in these challenging cases.

Integrated multi-omics profiling reveals a clinically relevant molecular feature and potential therapeutic target on phyllodes tumors of breast.

Phyllodes tumors (PTs) has an increased risk of local relapse and distant metastases. Molecular features correlating to histologic grade and aggressive behavior of PTs are poorly characterized. Here, whole exome sequencing (WES) was performed to explore genetic mutations in 61 samples of fibroepithelial breast tumors, including 16 fibroadenomas (FAs), 18 benign PTs, 19 borderline PTs, and 8 malignant PTs. Our work clearly shows that FA, benign PT, borderline PT, and malignant PT are independent entities at the genomic level. They may exist as hidden sub-clones carrying specific genetic alterations. Malignant PT-specific mutations present a multi-gene co-mutational pattern suggesting a synergistic effect of co-mutated genes in processes associated with malignant behavior. Moreover, we made a combined genomic and transcriptomic analysis, which presented a mutated gene-based interaction with expression profiles. We found that EGFR mutations (c.710C > T, c.758A > G, c.1295A > G, and c.2156G > C) serve as a hub of interaction network in borderline PTs, which suggests EGFR tyrosine kinase inhibitors (EGFRi) might be effective for borderline PTs. We found TP53 mutations (c.730G > T, c.844C > T, and c.1019delA) serves as a hub event of molecular changes of malignant PTs. Thus, our study based on the omics platforms of genome and transcriptome provides a better understanding of relapse process and the potential targeted therapy in PTs, which is pivotal in improving molecular-guided patient selection and designing clinically relevant combination strategies.

Malignant phyllodes tumor of the breast with predominant osteosarcoma and chondrosarcomatous differentiation: a rare case report and review of literature.

Background: Phyllodes tumors (PTs), which account for less than 1% of mammary gland tumors, composed of both epithelial and stromal components. If a malignant heterologous component is encountered, PT is considered malignant. Malignant phyllodes tumors (MPTs) only account for 8% to 20% of PTs. We report a case of MPT with osteosarcoma and chondrosarcoma differentiation and review the literature to discuss the differential diagnosis and therapy. Case presentation: A 59-year-old Chinese woman come to our hospital because of a palpable mass she had had for 1 months in the left breast. Preoperative core needle biopsy (CNB) was performed on the left breast mass on January 11, 2023. Pathological diagnosis was malignant tumor, the specific type was not clear. Mastectomy and sentinel lymph node biopsy of the left breast was performed. No metastasis was found in 3 sentinel lymph nodes identified by carbon nanoparticles and methylene blue double staining. Heterologous osteosarcoma and chondrosarcomatous differentiation of phyllodes tumor were observed. Immunohistochemistry: spindle tumor cells ER(-), PR(-), HER-2(-), CK-pan(-), CK7(-), CK8(-), SOX10(-), S100(-), and MDM2(-), CK5/6(-), P63(-), P40(-) were all negative. CD34:(+), SATB2(+), P53(90% strong), CD68 (+), Ki-67(LI: about 60%). No ductal carcinoma in situ was found in the breast. Fluorescence in situ hybridization (FISH) indicated USP6 was negatively expressed on formalin-fixed, paraffin-embedded (FFPE) tissue sections. Conclusion: MPTs are rare, and heterologous differentiation in MPTs is exceedingly rare. It could be diagnosed by pathology when metaplastic carcinoma, primary osteosarcoma, or myositis ossificans were excluded. This case could help clinicians to improve the prognosis and treatment of this disease.

Multi-recurrent Asynchronous Bilateral Malignant Phyllodes.

In this comprehensive study, we present an exceptionally rare case characterized by the occurrence of multi-recurrent asynchronous bilateral malignant phyllodes tumors. Phyllodes tumors, known for their rapid growth, originate within the stromal tissue of the breast and predominantly manifest as benign entities. Our case stands out as an extraordinary anomaly, not only due to its bilateral malignant nature but also owing to the manifestation of a multi-recurrent pattern on both sides. This unprecedented presentation underscores the complexity and heterogeneity of malignant phyllodes tumors, necessitating further in-depth investigation to unravel the underlying mechanisms driving their aggressive behavior and to explore innovative therapeutic strategies aimed at optimizing patient outcomes and prognosis.