A case of phyllodes tumor with rapid growth during pregnancy and lactation period: a case report.

BACKGROUND: The age of onset of the phyllodes tumor is generally in the late 40 s, and diagnosis and treatment during pregnancy and lactation are rare. We herein present a case of a phyllodes tumor that rapidly increased in size during the pregnancy and lactation period. CASE PRESENTATION: A 39-year-old woman was referred to our hospital with a mass in the right breast that increased in size during the pregnancy and lactation period. On ultrasound (5 week postpartum), a well-defined lobulated mass with internal septations and fluid retention was observed. Magnetic resonance imaging of the breast at 8 week postpartum revealed a 70-mm-sized smooth-margin mass with multilocular cystic components. Marked proliferation of stromal cells with high cell density was observed in a biopsy specimen taken at the previous hospital. We diagnosed the mass as a phyllodes tumor of borderline malignancy and excised it at 13 week postpartum. The excised tumor was 85 mm in diameter and its interior was filled with a milk-like substance. Histologically, there was only a mild increase in stromal cell density but fibrosis with associated degeneration was prominent. The final diagnosis was benign phyllodes tumor with degeneration. CONCLUSIONS: We report a case of a phyllodes tumor that rapidly increased in size during pregnancy and the lactation period. The accumulation of a milk-like substance was thought to be responsible for the rapid growth of the tumor.

Ductal carcinoma in situ and invasive carcinoma originating in a Fibroadenoma with concurrent benign phyllodes tumor: A case report.

INTRODUCTION AND IMPORTANCE: This case report presents a rare occurrence of multiple bilateral breast fibroadenomas, one evolving into ductal carcinoma in situ (DCIS) and invasive carcinoma, occurring simultaneously with a benign phyllodes tumor in the same breast. The importance of this case lies in emphasizing the crucial need for surveillance in patients with a long history of fibroadenomas and the necessity to investigate any rapid change in the size of fibroadenoma. CASE PRESENTATION: A 35-year-old multiparous female with a 17 year history of bilateral multiple breast lumps presented with recent onset of right breast pain and yellowish nipple discharge. Two lumps in her right breast had demonstrated an increase in size. Examination revealed a significant mass in the retroareolar region of the right breast and another at the 2 o'clock position. Histopathological examination of the biopsy specimens revealed fibroadenoma and benign phyllodes tumor. The patient underwent a bilateral breast lumpectomy. Further histopathological examination revealed ductal carcinoma in situ and invasive carcinoma within a complex fibroadenoma in the right breast and benign phyllodes tumor. Sentinel lymph node biopsy was negative. She had adjuvant radiations and trastuzumab. Regular follow-ups show no recurrence. CLINICAL DISCUSSION: Fibroadenomas are usually benign but rarely undergo malignant change. Quick response to size changes and early detection greatly enhance patient results. CONCLUSION: Ductal carcinoma in situ and invasive breast cancer, a rare malignancy found within a fibroadenoma, necessitates histopathological specimens and immunohistochemical results for accurate diagnosis. Survival rates are significantly enhanced through a multidisciplinary approach.

A Rare Case of High-Grade Spindle Cell Sarcoma of the Breast: A Case Report.

Introduction: Spindle cell sarcomas are rare breast lesions which are difficult to diagnose due to resemblance with other breast lesions. Histopathological examination and immunohistochemical staining are essential for diagnosis. Case Presentation: We present a rare case of a 15-year-old female presenting with high-grade rapidly progressive spindle cell sarcoma of the breast, differentiated as phyllodes tumor, with axillary lymph node involvement. Her lesion, on the left breast, measured 16.9 × 10.1 × 13.7 cm. Histology revealed malignant neoplasm arranged in sheets and individual neoplastic cells with an epithelioid to spindled morphology with scant cytoplasm and irregular nuclear membranes. Immunohistochemistry showed weakly positive focal CD-99, and negative WT-1, Myogenin, Desmin, p63, Cytokeratin, Synaptophysin, and CD-34 markers. She was successfully managed with modified radical mastectomy and discharged with regular follow-up advised. Conclusion: Spindle cell sarcomas have a very aggressive course and prompt diagnosis, and management is mandatory for better patient outcomes. Modified radical mastectomy is the mainstay of treatment.

microRNAs expression profile in phyllodes tumors of the breast.

Proliferation of both stromal and epithelial components is a characteristic of fibroepithelial cancers of the breast. Certain fibroepithelial tumors of the breast, such as fibradenomas and phyllodes tumors, are challenging to distinguish and categorize. To find biomarkers for early diagnosis and improved disease management, it is crucial to deepen our understanding of the molecular pathogenesis pathways and tumor biology of PTs. It has been demonstrated that microRNAs (miRNAs) have significant roles in cancers; the expression pattern of miRNAs can help with cancer categorization and treatment. In contrast, little is understood about miRNAs in breast fibroepithelial cancers. This study was conducted retrospectively with the goal of assessing the expression of six mature miRNAs (hsa-miR-21, hsa-miR-155, hsa-miR-182, hsa-miR-34a, hsa-miR-148a, and hsa-miR-205) in breast fibroepithelial cancers using real-time PCR and predicting these miRNAs' targets using computational techniques. This study comprised 64 patients in total-55 with phyllodes tumors and 9 with fibroadenoma. The research was carried out at the Farhat Hached University Hospital's pathology department in Tunisia. These particular miRNAs expression levels were evaluated via qRT-PCR, and in silico techniques were utilized to predict potential miRNA targets. Analysis of miRNA expression in fibroadenoma and phyllodes tumor tissues revealed that miR-21, miR-155 and miR-182 were upregulated in PTs compared to fibroadenoma and normal tissues. We reported that miR-34a, miR-148a and miR-205 were downregulated in both borderline and malignant PTs compared to fibroadenoma and normal tissue. In silico miRNA target prediction suggested the involvement of these molecules in a wide context of cell signaling pathways.

Emergency Resection of a Bleeding Ruptured Malignant Phyllodes Tumor of the Breast.

Ruptured phyllodes tumors, though extremely rare, can necessitate emergency surgery in certain cases, particularly those with active bleeding. A 51-year-old woman presented to our hospital with a newly identified mass in her right breast that developed over the past two months. The tumor had ruptured through the paramammary nipple. While initially diagnosed with a phyllodes tumor and scheduled for elective surgery, she experienced active bleeding from the ruptured tumor, leading to a drop in hemoglobin levels. An emergency right simple mastectomy was performed to control the bleeding. Postoperatively, no complications or recurrences were observed. Phyllodes tumors, which are characterized by rapid growth, may present with active bleeding following rupture and may require emergency surgery.

Real-world data on malignant and borderline phyllodes tumors of the breast: A population-based study of all 921 cases in the Netherlands (1989 -2020).

AIM: The aim of our study is to analyze patterns in treatment and outcome in a population-based series of patients with borderline and malignant phyllodes tumors (PT). MATERIAL AND METHODS: Data on all patients with a borderline or malignant PT (1989-2020) were extracted from the Netherlands Cancer Registry and the Dutch nationwide pathology databank (Palga) and retrospectively analyzed. RESULTS: We included 921 patients (borderline PT n = 452 and malignant PT n = 469). Borderline PT patients more often had breast-conserving surgery (BCS) as final surgery (81 vs. 46%). BCS rates for borderline PT increased over time (OR 1.08 per year, 95%CI 1.04 - 1.13, P < 0.001). In malignant PT adjuvant radiotherapy was given in 14.7%; this rate increased over time (OR 1.07 per year, 95%CI 1.02 - 1.13, P = 0.012). Local recurrence rate (5-year estimate of cumulative incidence) was 8.7% (95%CI 6.0-11.4) for borderline PT and 11.7% (95%CI 8.6-14.8) for malignant PT (P = 0.187) and was related to tumor size ≥ 20 mm (HR 10.6 (95%CI 1.5-76.8) and positive margin (HR 3.0 (95%CI 1.6-5.6), p < 0.001), but not to negative margin width (HR 1.3 ( 95%CI 0.7-2.3), p = 0.350)). Distant metastasis occurred only in malignant PT with a 5-year cumulative incidence of 4.7% (95%CI 3.3 - 6.1). CONCLUSION: This population-based series showed an increase in BCS in borderline PT and an increase in adjuvant radiotherapy in malignant PT over time. We identified malignant PT, BCS, larger tumor size and positive final margins as possible risk factors for local recurrence. Small but negative margins can be accepted.

Malignant phyllodes tumor and invasive lobular breast carcinoma: Morpho-molecular characterization of an uncommon collision tumor and review of the literature.

Phyllodes tumor (PT) of the breast is a biphasic neoplasia composed of mesenchymal and epithelial cells. PTs are graded as benign, borderline or malignant according to histological criteria. Invasive lobular carcinoma (ILC) is a special breast cancer subtype defined by non-cohesive growth and loss of E-cadherin. PT is treated by resection. ILC is treated by resection and adjuvant endocrine therapy with or without chemotherapy. Collision tumors composed of PT and concurrent ILC are rare. Due to their dissociated growth, ILC cells may escape histologic detection when admixed with PTs. Here we report the case of a 71-years-old female diagnosed with a PT/ILC collision tumor. The patient presented with a tumor in the right breast. A core needle biopsy showed mesenchymal spindle cell proliferates suspicious for a PT. The resection specimen confirmed a malignant PT with stromal overgrowth. Unexpectedly, the resection specimen also revealed sparse infiltrates of ILC admixed with the PT. Immunohistochemistry of mesenchymal PT cells and ILC cells was consistent with the histomorphological diagnosis. Molecular analyses demonstrated a IDH1 variant of unknown significance and GNAS gene mutation in microdissected PT tissue. ILC tissue showed wild-type IDH1 and GNAS, but harbored CDH1/E-cadherin and TP53 gene mutations, arguing against clonal relatedness of the two lesions. Review of the literature identified six reported PT/ILC collision tumors, involving three benign, two borderline and one malignant PT. In summary, this is the second report on a malignant PT/ILC collision tumor. Correct histologic diagnosis of PT/ILC collision tumors is clinically relevant, because adjuvant endocrine therapy is mandatory for ILC.

Malignant Phyllodes Tumor in a Pubertal Girl: A Report of a Case.

BACKGROUND: Malignant phyllodes tumor (MPT) is a rare breast disease that is extremely rare in children. A few cases of pediatric malignant phyllodes tumors have been reported, including some with a poor prognosis. CASE: A 14-year-old girl presented with a growing lump on her right breast. On the basis of imaging tests and a core needle biopsy, MPT was diagnosed, and right mastectomy was performed. The postoperative course was uneventful. SUMMARY AND CONCLUSION: MPT is an infrequent disease in adult females and is extremely rare in pubertal females. It occasionally shows rapid growth, metastasis, and recurrence with a poor prognosis. Early surgical resection is necessary to obtain a cure. When a rapidly growing breast tumor is observed in pubertal females, MPT should be considered.

Better survival was found in patients treated with breast-conserving surgery compared with mastectomy in malignant phyllodes tumor of the breast.

Malignant phyllodes tumor of the breast (MPTB) is a rare type of breast cancer. The prognosis between breast-conserving surgery (BCS) and mastectomy remains unclear in MPTB. Therefore, long-term survival was investigated between BCS and mastectomy in MPTB via the Surveillance, Epidemiology, and End Results (SEER) database. MPTB patients with T1-2/N0 stage between 2000 and 2015 from SEER database were retrospectively reviewed. Prognosis between different surgical approaches was assessed by Kaplan-Meier curves and Cox proportional hazards analysis. A total of 795 patients were enrolled with a median follow-up of 126 months. BCS was associated with significantly increased 10-year overall survival (OS) (89.2% vs. 81.1%, p = 0.002) and breast cancer-specific survival (BCSS) (95.2% vs. 90%, p = 0.004) compared with mastectomy. Multivariate analysis showed better OS (HR = 0.587, 95% CI 0.406-0.850, p = 0.005) and BCSS (HR = 0.463, 95%CI 0.267-0.804, p = 0.006) in the BCS group than the mastectomy group. After 1:1 propensity score matching (PSM), improved 10-year OS (89.2% vs.81%, p = 0.023) and BCSS (95.8% vs. 90.1%, p = 0.033) were observed in BCS compared with mastectomy. This study found the survival benefit of BCS over mastectomy in patients with early-stage MPTB. BCS should be recommended as a priority in MPTB patients when both surgical approaches are feasible.

Is wide excision really needed? Correlation between resection margin and recurrence in benign phyllodes tumors of the breast.

Purpose: Phyllodes tumors are similar to fibroadenomas in imaging and in pathological characteristics and are difficult to identify preoperatively. The purpose of this study was to analyze the recurrence rate after excision stratified by the surgical margin width and to propose and emphasize the "wait and watch" treatment strategy for benign phyllodes tumors. Methods: We performed a retrospective cohort study of patients diagnosed with benign phyllodes tumors by surgical excision between January 2000 and December 2022 at our institution. The medical and histopathological records were reviewed. Results: The results were obtained using the Cox proportional hazard regression and logistic regression. Resection margin status and recurrence were the independent variables. In each variable selection model, the resection margin was positive or less than 1 cm, and the recurrence rate was 3.7 and 1.04 times higher than the control group, but the difference was not statistically significant in 2 analyses. Conclusion: The surgical resection margin status of benign phyllodes tumors did not significantly affect locoregional recurrence. Therefore, follow-up imaging at short intervals without additional surgery is a feasible clinical option when the surgical resection margin is positive or less than 1 cm.

A Rare Presentation of Cutaneous Scalp Metastasis From a Malignant Phyllodes Tumor of the Breast: A Case Report and Literature Review.

This report presents a unique case of a 56-year-old female diagnosed with a malignant phyllodes tumor (PT). Following a modified radical mastectomy, the patient exhibited metastasis to the lungs, bones, and, uncommonly, the scalp. Despite treatment interventions, including chemotherapy and radiotherapy, the patient's condition progressed, underscoring the aggressive nature of malignant PTs. This case emphasizes the importance of recognizing unusual metastatic sites and the challenges in managing such aggressive tumors.

Importancia del diagnóstico diferencial de los tumores fibroepiteliales mamarios en adolescentes. Descripción de un caso / Importance of the differential diagnosis of breast fibroepithelial tumors in adolescents: Clinical case

El fibroadenoma es la lesión benigna fibroepitelial más frecuente de la mama en la mujer joven, correspondiendo alrededor del 90% de las lesiones sólidas de la glándula en la adolescencia. Sin embargo, el fibroadenoma gigante juvenil es una afección de la glándula mamaria poco frecuente, que afecta principalmente a mujeres menores de 18 años. Debido a la similitud de las características clínicas del fibroadenoma gigante juvenil y el tumor filodes, además del rápido crecimiento de ambas entidades, es importante establecer el diagnóstico diferencial de ambas enfermedades cuando se sospeche de alguna de ellas, con la finalidad de garantizar la actitud terapéutica más adecuada. Adolescente de 14 años de edad sin antecedentes familiares ni personales de interés, quien acude remitida a nuestra consulta en septiembre del 2021 en vista de hallazgos ecográficos, por presentar asimetría mamaria a expensas de nódulo mamario izquierdo de 5 meses de evolución. Se realiza biopsia por aguja gruesa ecoguiada con el resultado de fibroadenoma gigante juvenil. Se practicó tumorectomía. El diagnóstico histopatológico se mostró con fibroadenoma gigante juvenil de mama izquierda. Basándonos en la bibliografía consultada y nuestra experiencia, un diagnóstico diferencial temprano y preciso, en conjunto a la extirpación quirúrgica para una correcta caracterización, sería el manejo más adecuado de estas pacientes. La táctica y técnica quirúrgica dependen de la edad al momento del diagnóstico, de las características clínicas y radiológicas de la glándula mamaria y del tumor, e inclusive de los deseos de la paciente. (AU)

Fibroadenoma is the most common benign fibroepithelial lesion of the breast in young women, accounting for around 90% of solid lesions of the gland in adolescence. However, juvenile giant fibroadenoma is a rare condition of the mammary gland, which mainly affects women under 18 years of age. Due to the similarity of the clinical characteristics of juvenile giant fibroadenoma and phyllodes tumor, in addition to the rapid growth of both. Entities, it is important to establish the differential diagnóstico of both pathologies when one of them is suspected, in order to guarantee the most appropriate therapeutic approach. A 14-year-old adolescent with no family or personal history of interest, who was referred to our clinic in September 2021 in view of ultrasound findings due to presenting breast asymmetry at the expense of a 5-month-old left breast nodule. An ultrasound-guided core needle biopsy was performed with the result of giant juvenile fibroadenoma. Lumpectomy was performed. Histopathological diagnóstico compatible with juvenile giant fibroadenoma of the left breast. Based on the consulted bibliography and our experience, an early and precise differential diagnóstico, together with surgical removal for a correct characterization would be the most appropriate management of these patients. The surgical tactics and technique depend on the age at the time of diagnóstico, the clinical and radiological characteristics of the mammary gland and the tumor, and even the wishes of the patient. (AU)

Breast development and disorders in children and adolescents.

Breast masses are infrequently encountered in pediatric and adolescent populations. Most breast masses in children are benign entities arising from embryological defects which can be managed once breast development is complete. Diagnostic and management dilemmas arise when fibroepithelial lesions of the breast are seen in clinical practice. Differentiation between a fibroadenoma and a phyllodes tumor is important to guide management. Breast cancer in children under 18 years of age is extremely rare and invasive diagnostic testing and aggressive management is only recommended when clinical suspicion of malignancy is very high. Patient and caregiver counseling plays an important role in the management of these diseases. While adult-onset breast diseases have been studied very closely, there is a dearth of literature on pediatric breast anomalies. This review aims to provide a scoping overview of the available literature on benign, fibroepithelial, and malignant lesions of the breast in pediatric and adolescent populations to help guide physicians and surgeons with decision-making regarding the diagnosis and management of pediatric breast diseases.

Metabolic coupling in phyllodes tumor of the breast and its association with tumor progression.

There are markers of metabolic coupling in breast cancer. Loss of caveolin-1 (Cav-1) and upregulation of monocarboxylate transporters (MCTs), especially MCT1 and MCT4, serve an important role in metabolic coupling necessary for release and uptake of metabolites. However, the occurrence of these phenomena in phyllodes tumors (PTs) of the breast is unclear. A total of 101 PTs (60 benign, 26 borderline and 15 malignant) and nine breast tissue samples with no pathological lesions were analyzed. Immunohistochemical staining for Cav-1, MCT1 and MCT4 was performed using tissue microarray and their expression in both stromal and epithelial components was assessed. Cav-1 expression in PTs demonstrated a significant decrease in the stromal component compared with that in the normal breast tissues (P<0.001). MCT1 expression in both epithelial and stromal components was significantly increased in PTs, compared with that in normal breast tissues (both P<0.001). Stromal MCT1 and MCT4 expression were different depending on tumor grade of PTs, and stromal MCT1 expression significantly increased with increasing tumor grade (P<0.001). Although not statistically significant, stromal Cav-1 expression notably decreased with increases in PT grade. High stromal MCT1 expression was significantly associated with lower disease-free survival rate in comparison with low stromal MCT1 expression (P<0.05). These results suggested that changes in protein expression of Cav-1, MCT1 and MCT4 may be associated with tumorigenesis and progression of PTs of the breast.

Distinguishing Fibroepithelial Lesions Requires Clinical, Imaging, and Pathology Correlation.

Phyllodes tumor (PT) is a rare tumor that can present as benign, borderline, or malignant. These tumors arise from the breast stroma, similar to fibroadenomas. Phyllodes tumors and fibroadenomas often have overlapping features in both radiological imaging and pathologic analysis. As a result, these two lesions are often difficult to differentiate and require the correlation of multiple modalities, including clinical context, radiologic imaging, and histological evaluation. This article presents a case of a borderline phyllodes tumor in a 51-year-old female, with the inclusion of its radiologic and pathologic images and performed treatment. The goal of this article is to provide a review of the clinical presentation, diagnostic imaging and pathology features, treatment, and management of a phyllodes tumor and compare and contrast this against the more common fibroadenomas, in order to provide aid for differentiating these two breast lesions.

Borderline Phyllodes Tumor in a Child.

Phyllodes tumor (PT) is considered a rare fibroepithelial tumor. Very few series have been reported in children and adolescents. Based on histopathological features, it can be classified as benign, borderline, or malignant, with the latter having a more aggressive clinical behavior. We report the case of a 10-year-old female who began with an asymptomatic mobile right breast mass. An initial fine needle biopsy (FNB) concluded fibroadenoma (FA). Months later, the mass kept growing, with the appearance of pain and nipple discharge. Benign PT was demonstrated in a new biopsy. A total mastectomy was performed. The post-surgical histopathological examination was compatible with a borderline PT. The patient is now symptom-free and with no signs of relapse. Not all breast masses in the pediatric or adolescent age bracket are FA. Attention is warranted when the clinical behavior does not follow the usual outline. PT has to be considered as a possible diagnosis and treated accordingly.

A rapidly growing fibroadenoma in a pregnant woman: A case report.

BACKGROUND: Fibroadenomas are the most common benign breast lesions in women. They present as a unilateral mass and can rapidly enlarge in size through hormonal changes. Fibroadenomas could be classified as small or giant, and as simple or complex. They are classified as 'giant' when the size exceeds 5 cm and/or weight 500 gram; and as 'complex' if one of the following characteristics is present: cysts with a size >3 mm, epithelial calcifications, sclerosing adenosis and papillary apocrine metaplasia. Giant fibroadenomas can cause compression of surrounding breast tissue or breast asymmetry, requiring surgical excision in order to preserve a normal breast shape. CASE: A 26-year-old pregnant woman was referred with a palpable mass of her right breast. The mass rapidly increased in size to a diameter of 13 cm during the second trimester of her pregnancy. A tru-cut biopsy confirmed a fibroadenoma. The rapid growth and compression of normal breast tissues indicated a lumpectomy during her pregnancy. The mass was easily excised without any consequences for the pregnancy. Pathological examination showed a complex giant fibroadenoma. CONCLUSION: A unique case of a pregnant woman with rapid progression of a fibroadenoma that met the criteria of a complex and giant fibroadenoma, was presented. This case emphasizes the importance of timely surgical intervention, even during pregnancy, to prevent permanent breast tissue damage.

CD146 promotes malignant progression of breast phyllodes tumor through suppressing DCBLD2 degradation and activating the AKT pathway.

BACKGROUND: As a rapid-progressing tumor, breast malignant phyllodes tumors (PTs) are challenged by the lack of effective therapeutic strategies and suitable prognostic markers. This study aimed to clarify the role and mechanism of CD146 on promoting PTs malignant progression, and to identify a novel prognosis marker and treatment target of breast malignant PTs. METHODS: The expression and prognostic significance of CD146 in PTs was detected through single-cell RNA-sequencing (scRNA-seq), immunostaining, real-time PCR and other methodologies. Functional experiments including proliferation assay, colony formation assay, transwell assay, and collagen contraction assay were conducted to validate the role of CD146 in malignant progression of PTs. The efficacy of anti-CD146 monoclonal antibody AA98 against malignant PTs was corroborated by a malignant PT organoid model and a PT patient-derived xenograft (PDX) model. Transcriptome sequencing, proteomic analysis, co-immunoprecipitation, and pull-down assay was employed to identify the modulating pathway and additional molecular mechanism. RESULTS: In this study, the scRNA-seq analysis of PTs disclosed a CD146-positive characteristic in the α-SMA+ fibroblast subset. Furthermore, a progressive elevation in the level of CD146 was observed with the malignant progression of PTs. More importantly, CD146 was found to serve as an independent predictor for recurrence in PT patients. Furthermore, CD146 was found to augment the viability and invasion of PTs. Mechanistically, CD146 acted as a protective "shield" to prevent the degradation of Discoidin, CUB, and LCCL domain-containing protein 2 (DCBLD2), thereby activating the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and enhancing malignant behaviors of PT cells. In the malignant PT organoid and PDX model, a significant suppression of malignant PT growth was observed after the application of AA98. CONCLUSIONS: These findings suggested that CD146 served as an efficacious marker for predicting PT malignant progression and showed promise as a prognosis marker and treatment target of breast malignant PTs. The study further unveiled the essential role of the CD146-DCBLD2/PI3K/AKT axis in the malignant progression of PTs.

Case Report: A 13-year-old adolescent diagnosed as malignant phyllodes tumor combined with rhabdomyosarcoma differentiation.

Phyllodes tumor (PT) is an infrequent type of breast neoplasm, constituting a mere 0.5%-1.5% of the entirety of breast tumors. The malignant phyllodes tumor (MPT) comprises only 15% of all phyllodes tumors, and its transformation into rhabdomyosarcoma (RMS) is exceedingly rare in clinical practice. Given its insensitivity to chemotherapy and radiotherapy, treatment options for MPT patients are limited, leaving complete surgical resection as the only option. Therefore, it is imperative to investigate the effective utilization of the heterogeneous differentiation characteristics of MPT to expand treatment alternatives for these patients. In this case report, we represent a 13-year-old adolescent diagnosed with giant breast MPT with RMS differentiation and pulmonary metastasis. The initial step in the treatment process involved radical surgical resection, followed by the administration of four cycles of VDC/IC chemotherapy, which is widely recognized as the standard chemotherapy for RMS. Regrettably, the delay in initiating chemotherapy resulted in minimal observable changes in the size of the pulmonary metastatic nodule. Additionally, a comprehensive literature review on the characterization of MPT with heterogeneous differentiation was conducted to enhance comprehension of the diagnosis and treatment of this uncommon disease in clinical practice. Meanwhile, this case also reminds the doctors that when we diagnose a patient as MPT, it is crucial to consider its heterogenous nature and promptly initiate adjuvant treatment. By targeting the differentiation element of MPT, it becomes feasible to overcome the previously perceived limitation of surgical intervention as the sole treatment option.